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November 9, 2026 at 9:00 pm On Sale Now
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Product Description
Yamatomichi Puff Smock
■Excerpt from the manufacturer's description
One of the world's lightest synthetic insulations, highly resistant to moisture
Synthetic insulation has evolved as a thermal material designed to address the weakness of natural down—its susceptibility to moisture. The Puff Smock is a mid-layer jacket that leverages these characteristics to deliver world-class lightness M just M size M —while maximizing thermal performance.
The filling features PrimaLoft® Rise sleeping bag insulation, which offers excellent loft per unit weight and provides high thermal insulation despite its light weight. The inner side of the outer fabric features a titanium sputtering finish that reflects the body’s radiant heat, and by using four layers of insulation around the neck and two layers in a large, insulated pocket at the abdomen, the sleeping bag enhances warmth where needed while maintaining its lightweight design.
On the other hand, this light weight comes with a trade-off. With lightweight synthetic insulation, repeated use and compression cause the loft of the fill to decrease over time. Please keep this characteristic in mind when taking advantage of its light weight.
■Stays Warm Even When Wet
In the mountains, the weather can take a sudden turn for the worse, and you may find yourself exposed to cold wind and rain. When you’re wet and exposed to cold winds, your body rapidly loses heat, which can sometimes lead to life-threatening conditions such as hypothermia.
Synthetic insulation has been developed as a thermal material designed to address one of the weaknesses of natural down: its susceptibility to moisture. While natural down loses its loft and thermal insulation properties when wet, the polyester fibers used in synthetic insulation are resistant to moisture absorption and tend to retain their loft even when wet, so their thermal insulation properties are less likely to diminish.
Rain isn’t the only thing that can get your insulated layer wet in the mountains. There’s also sweat, a wet shell jacket, and condensation inside your tent. With the Puff Smock, you don’t have to worry too much about it getting a little wet, so you can store it in an easily accessible spot—like the top of your backpack or an outside pocket—and slip it on right away when you need it, expanding the range of situations where you can use your insulated layer.
■ Apply a thick layer to the areas you want to insulate
Instead of making the entire garment thicker, use one layer of batting in the regular areas, two layers in the abdominal area, and four layers around the neck. In the diagram, the number of batting layers is indicated by the shade of red.
■Four layers around the neck
To enhance warmth, the neck area features a double layer of insulation in both the collar and the neck baffle, creating a four-layer structure.
■Divide the abdomen into two layers
The large, padded pocket in the abdominal area creates a double layer of padding, which not only enhances warmth in the abdomen but also warms cold hands.
■Details of Each Part
・Offset zipper: The zipper is offset so it doesn't rub against your chin when closed.
・Kangaroo pocket with a zipper: A kangaroo pocket with a zipper that pulls up to close, designed to keep items from falling out.
・Drawstring inside the pocket: A drawstring inside the kangaroo pocket used to cinch the hem.
■Materials
・表地：Pertex(R) Quantum, Titanium Coated, 24g/m2, C0 DWR（耐久性撥水加工）
・中綿：PrimaLoft(R) RISE Sleeping Bag, 40g/m2
・Lining: Pertex® Quantum, 24 g/m², C0 DWR (durable water-repellent finish)
Zipper: YKK #3 Coil Zipper
■Weight
・173g (Size XS)
・188g (Size S)
・196g (Size M)
・208 g (Size L)
・225 g (Size XL)
■Product Dimensions (cm)
[XS] Length: 64, Chest: 53.5, Hem: 43, Sleeve Length: 80.5, Cuff Width: 8
[S] Length: 68, Chest: 56, Hem: 45.5, Sleeve Length: 84.5, Cuff Width: 8.5
[M] Length: 70, Chest: 58.5, Hem: 47, Sleeve Length: 87, Cuff Width: 9
[L] Length: 72, Chest: 62.5, Hem: 50.5, Sleeve Length: 90, Cuff Width: 9.5
[XL] Length: 75, Chest: 65, Hem: 52.5, Sleeve Length: 93, Cuff Width: 10
*This is the elastic rise measurement taken without stretching the elastic at the hem.
*From the manufacturer's website*
■Precautions for Use
・Please use this as a standby item.
The Puff Smock is designed as a warm layer for when you're taking a break, at the campsite, or before setting out in the morning—in other words, during periods of inactivity.
If you wear it continuously while being active, body movement and friction may cause the insulation to twist or shift, which could reduce its loft and thermal performance.
・Do not compress too tightly
The Puff Smock is designed to be compressed to some extent inside a backpack when carried, but please avoid forcing it into spaces that are too small or compressing it excessively using a compression sack or similar item.
Because it is made of lightweight synthetic fiber fill, the filling may become damaged and lose its loft due to heavy compression or repeated stress on the same area.
・Do not store items while they are compressed.
After wearing it or after a hike, remove it from your backpack or stuff sack immediately to restore the loft of the insulation.
If stored in a compressed state for an extended period, the filling may become difficult to restore to its original shape, which could reduce its loft and insulation performance. Please do not compress the item when storing it; store it in a loose, uncompressed state.
■Product Care
Because this product uses lightweight yet highly lofted filling, washing it in a washing machine may cause the filling to shift or clump due to agitation and friction during the wash and rinse cycles, which could reduce its loft.
In addition, the titanium coating applied to the reverse side of the outer fabric will gradually wear off due to repeated friction caused by washing and other activities. To minimize stress on the filling and the titanium coating and keep the product in good condition for as long as possible, please be sure to wash and rinse it by hand.
・Please hand-wash this item; do not use a washing machine.
・Use a mild detergent and gently wash by pressing the fabric in lukewarm water at around 30°C.
・Please avoid rubbing the fabric or wringing it out forcefully.
・Do not apply undiluted detergent or let the item soak for long periods of time, as the detergent ingredients may cause the titanium to lift.
・Please avoid using fabric softener and bleach.
・For areas with stains, gently spot-clean them with a laundry brush or a soft sponge.
・Be sure to rinse thoroughly to ensure no detergent residue remains.
・To remove excess water, do not wring the item out; instead, wrap it in a towel and gently press to absorb the moisture.
・Shape the item and hang it to dry in a well-ventilated, shaded area.
・Do not iron or dry clean.
*Please note that since we are using manufacturer images, the actual product may differ slightly in terms of specifications (such as logo placement, color, or pattern placement).
■Excerpt from the manufacturer's description
One of the world's lightest synthetic insulations, highly resistant to moisture
Synthetic insulation has evolved as a thermal material designed to address the weakness of natural down—its susceptibility to moisture. The Puff Smock is a mid-layer jacket that leverages these characteristics to deliver world-class lightness M just M size M —while maximizing thermal performance.
The filling features PrimaLoft® Rise sleeping bag insulation, which offers excellent loft per unit weight and provides high thermal insulation despite its light weight. The inner side of the outer fabric features a titanium sputtering finish that reflects the body’s radiant heat, and by using four layers of insulation around the neck and two layers in a large, insulated pocket at the abdomen, the sleeping bag enhances warmth where needed while maintaining its lightweight design.
On the other hand, this light weight comes with a trade-off. With lightweight synthetic insulation, repeated use and compression cause the loft of the fill to decrease over time. Please keep this characteristic in mind when taking advantage of its light weight.
■Stays Warm Even When Wet
In the mountains, the weather can take a sudden turn for the worse, and you may find yourself exposed to cold wind and rain. When you’re wet and exposed to cold winds, your body rapidly loses heat, which can sometimes lead to life-threatening conditions such as hypothermia.
Synthetic insulation has been developed as a thermal material designed to address one of the weaknesses of natural down: its susceptibility to moisture. While natural down loses its loft and thermal insulation properties when wet, the polyester fibers used in synthetic insulation are resistant to moisture absorption and tend to retain their loft even when wet, so their thermal insulation properties are less likely to diminish.
Rain isn’t the only thing that can get your insulated layer wet in the mountains. There’s also sweat, a wet shell jacket, and condensation inside your tent. With the Puff Smock, you don’t have to worry too much about it getting a little wet, so you can store it in an easily accessible spot—like the top of your backpack or an outside pocket—and slip it on right away when you need it, expanding the range of situations where you can use your insulated layer.
■ Apply a thick layer to the areas you want to insulate
Instead of making the entire garment thicker, use one layer of batting in the regular areas, two layers in the abdominal area, and four layers around the neck. In the diagram, the number of batting layers is indicated by the shade of red.
■Four layers around the neck
To enhance warmth, the neck area features a double layer of insulation in both the collar and the neck baffle, creating a four-layer structure.
■Divide the abdomen into two layers
The large, padded pocket in the abdominal area creates a double layer of padding, which not only enhances warmth in the abdomen but also warms cold hands.
■Details of Each Part
・Offset zipper: The zipper is offset so it doesn't rub against your chin when closed.
・Kangaroo pocket with a zipper: A kangaroo pocket with a zipper that pulls up to close, designed to keep items from falling out.
・Drawstring inside the pocket: A drawstring inside the kangaroo pocket used to cinch the hem.
■Materials
・表地：Pertex(R) Quantum, Titanium Coated, 24g/m2, C0 DWR（耐久性撥水加工）
・中綿：PrimaLoft(R) RISE Sleeping Bag, 40g/m2
・Lining: Pertex® Quantum, 24 g/m², C0 DWR (durable water-repellent finish)
Zipper: YKK #3 Coil Zipper
■Weight
・173g (Size XS)
・188g (Size S)
・196g (Size M)
・208 g (Size L)
・225 g (Size XL)
■Product Dimensions (cm)
[XS] Length: 64, Chest: 53.5, Hem: 43, Sleeve Length: 80.5, Cuff Width: 8
[S] Length: 68, Chest: 56, Hem: 45.5, Sleeve Length: 84.5, Cuff Width: 8.5
[M] Length: 70, Chest: 58.5, Hem: 47, Sleeve Length: 87, Cuff Width: 9
[L] Length: 72, Chest: 62.5, Hem: 50.5, Sleeve Length: 90, Cuff Width: 9.5
[XL] Length: 75, Chest: 65, Hem: 52.5, Sleeve Length: 93, Cuff Width: 10
*This is the elastic rise measurement taken without stretching the elastic at the hem.
*From the manufacturer's website*
■Precautions for Use
・Please use this as a standby item.
The Puff Smock is designed as a warm layer for when you're taking a break, at the campsite, or before setting out in the morning—in other words, during periods of inactivity.
If you wear it continuously while being active, body movement and friction may cause the insulation to twist or shift, which could reduce its loft and thermal performance.
・Do not compress too tightly
The Puff Smock is designed to be compressed to some extent inside a backpack when carried, but please avoid forcing it into spaces that are too small or compressing it excessively using a compression sack or similar item.
Because it is made of lightweight synthetic fiber fill, the filling may become damaged and lose its loft due to heavy compression or repeated stress on the same area.
・Do not store items while they are compressed.
After wearing it or after a hike, remove it from your backpack or stuff sack immediately to restore the loft of the insulation.
If stored in a compressed state for an extended period, the filling may become difficult to restore to its original shape, which could reduce its loft and insulation performance. Please do not compress the item when storing it; store it in a loose, uncompressed state.
■Product Care
Because this product uses lightweight yet highly lofted filling, washing it in a washing machine may cause the filling to shift or clump due to agitation and friction during the wash and rinse cycles, which could reduce its loft.
In addition, the titanium coating applied to the reverse side of the outer fabric will gradually wear off due to repeated friction caused by washing and other activities. To minimize stress on the filling and the titanium coating and keep the product in good condition for as long as possible, please be sure to wash and rinse it by hand.
・Please hand-wash this item; do not use a washing machine.
・Use a mild detergent and gently wash by pressing the fabric in lukewarm water at around 30°C.
・Please avoid rubbing the fabric or wringing it out forcefully.
・Do not apply undiluted detergent or let the item soak for long periods of time, as the detergent ingredients may cause the titanium to lift.
・Please avoid using fabric softener and bleach.
・For areas with stains, gently spot-clean them with a laundry brush or a soft sponge.
・Be sure to rinse thoroughly to ensure no detergent residue remains.
・To remove excess water, do not wring the item out; instead, wrap it in a towel and gently press to absorb the moisture.
・Shape the item and hang it to dry in a well-ventilated, shaded area.
・Do not iron or dry clean.
*Please note that since we are using manufacturer images, the actual product may differ slightly in terms of specifications (such as logo placement, color, or pattern placement).
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Cancellations, Returns, and Exchanges
Before Placing Your Order
As a general rule, we do not accept returns or exchanges of merchandise for reasons related to the customer’s preferences, such as “it didn’t look like I expected” or “the size doesn’t fit.” If you have any questions or concerns, please consult with our staff first.
Please place your order after understanding and agreeing to the following points.
・Depending on the device or environment you are using, the color and texture of the product may appear slightly different.
・There may be slight variations in the dimensions listed in the product description.
・Minor scratches or scuffs may occur during the manufacturing process.
・Depending on the material of the product, there may be variations in color, texture, or pattern from item to item.
Order Cancellation
As a general rule, we do not accept cancellations after a shipping confirmation email has been sent.
We make every effort to manage our inventory, but if we are unable to secure the items you ordered for unavoidable reasons, we may have to cancel your order.
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We may impose purchase limits on certain products. Orders placed from multiple accounts believed to belong to the same person, or orders suspected of using bots, may be canceled or the quantity reduced.
*Please note that we assume no liability or responsibility for any losses, damages, or other adverse consequences resulting from a cancellation.
Returns and Exchanges
While we take the utmost care to ensure the quality of our products and their packaging, in the unlikely event that a product arrives damaged or soiled, or if you receive an item different from what you ordered, please contact us via the “Contact Form ” within 7 days of the delivery date. We will cover all associated costs.
・If a replacement item is available, we will replace the item.
・If we are unable to secure a replacement, we will issue a refund.
Please note that we cannot accept returns or exchanges if any of the following conditions apply. We appreciate your understanding.
・If more than 8 days have passed since the product was delivered
・When we determine that the customer has finished using the product
・If the item has been altered, washed, or dry-cleaned
・If any accessories (product tags, warranty cards, bags, boxes, etc.) are lost or damaged
・If odors, scratches, or stains occur while the item is in the customer's possession
・Items that come into direct contact with the skin, such as underwear, socks, and accessories, as well as perfumes and cosmetics, etc.
・If the item is returned without prior notice
About the Listed Prices
We take every precaution to ensure that the product information displayed on this site is accurate. However, in the unlikely event that we discover after payment has been processed that the product price was incorrectly displayed on the site, we will contact you and either adjust the price to the correct amount and process the payment, or cancel your order.
Important Notes
*Please note that inventory for this item is shared across our physical stores and other shopping sites operated by our company. We check inventory after receiving your order, so there is a possibility that the item may be out of stock. In such cases, we apologize for the inconvenience and will notify you via email. Thank you for your understanding.
