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Arata ASP-R5 Mummy
■Excerpt from the manufacturer's description
Taking the balance of lightness and warmth to the next level
All-Season Air Pad ASP-R5 Series
Rated for -20°C; 9.5 cm thick
An all-season air pad suitable for most situations
The R5-class air pad can be used in Japan even during the harsh winter months at altitudes of around 2,000 meters, and since it is suitable for most regions, seasons, and environments around the world, it is an extremely versatile item.
As a result, various companies offer products designed to meet these needs, but the ASP-R5 stands out among them by achieving the highest level of balance between weight, R-value, and durability, all while remaining reasonably priced.
We’ve also taken care to ensure you can choose the mat that best suits your body type and lifestyle.
The "Regular" style: a spacious rectangular design
"Mummy"—designed to fit the human body, with unnecessary parts removed to achieve a lightweight finish
"Regular Short" is ideal for petite people or those who are tall but don't need their heads covered.
The “Regular Extra Short” is perfect for users who prefer a shorter length from head to toe, as well as for carrying as a spare tire for group hikes.
We offer a total of four sizes.
The ASP-R5 is the perfect choice for first-time air mat buyers and those looking to switch from older-generation air pads to a lighter option.
■Technical Note
○ Achieving a higher level of balance between R-value and weight while ensuring a comfortable sleeping experience
The development goal for the ASP-R7 was to ensure thermal insulation capable of withstanding temperatures as low as -30°C; however, it became clear that the structure adopted for the R7 did not achieve the optimal balance between weight and R-value. Therefore, the next goal was to achieve the highest possible balance between weight and R-value.
Although the ASP-R5 and R8 use the same air pad as the ASP-R7, their internal structures are completely different. The cross-sectional structure is very simple: a PET film with a heat-reflective coating is sandwiched between the top and bottom fabrics, reflecting heat rays while preventing convection of the internal air. The ASP-R5 features two layers of this film. While simple, this design is highly efficient and currently offers the best balance between weight and R-value.
For the ASP-R5 and R8, we have designed these models using this structure, paying close attention to every detail of the internal dimensions to ensure the highest levels of comfort, weight, and pressure resistance.
○ Top-tier performance—both in terms of specifications and beyond—: The Pursuit of Pressure Resistance
As mentioned earlier, in the development of the ASP-R5, we are striving to achieve the highest possible balance between weight and R-value—as reflected in the specifications—while also pursuing performance characteristics that go beyond the specifications.
When it comes to air pads, if you focus solely on weight and R-value, it’s easy to create a product that’s ultra-lightweight and has a high R-value. However, if you prioritize those factors alone, comfort and pressure resistance will suffer.
While pressure resistance is not something that the average user typically thinks about, manufacturing plants that produce hundreds of thousands or even millions of units annually and receive feedback from the market know that this is the most common issue and that it is a performance characteristic that should be prioritized over tear strength.
The ASP-R5 and R8 were developed with a particular focus on pressure resistance, in addition to comfort. Regarding their structure, we determined the specific design details by actually testing our own previous development samples, various products on the market, and development samples from our manufacturing plants. While we won’t reveal the design philosophy in detail, the products were designed based on surprisingly detailed calculations, and we have verified their effectiveness.
○ Choosing the right materials was the most challenging part of achieving our goal
Surprisingly, the biggest challenge in developing the ASP-R5 was the most basic fabric.
There is little point in using high-cost materials on par with the world’s finest products and achieving equivalent performance at an equivalent cost. At the start of development, there was no fabric that met the cost requirements in addition to tear strength, weight, and weld strength.
Although it was a very tedious and time-consuming process, advances in coating technology and improvements in quality control at our manufacturing plant have enabled us to produce products using materials that meet the requirements.
They are inflated to a pressure more than three times that of standard automotive tires, held at that pressure for a set period, and then completely deflated. The ASP-R5 and R8 are lightweight, yet have been confirmed to maintain their functionality even after thousands of repetitions of this rigorous cycle.
○ A mummy-style sleeping bag that prioritizes comfort and does not prioritize excessive weight reduction
We also offer a mummy-style model for users seeking a lightweight option, though we have not prioritized excessive weight reduction. The overall width is set at 51 cm—a standard measurement for mummy-style sleeping bags—with a simple semicircular shape around the head and a gentle taper from the knees down. This design balances weight reduction with a fit that helps prevent the sleeper from slipping out of the sleeping bag.
○ Simple Pump Sack
The pump sacks for the ASP-R5 and R8 are designed to seal more easily around the air intake, making it easier to transfer the air from the pump sack into the pad without letting any air escape. They weigh approximately 80g.
If weight is a concern, we recommend purchasing the “Airpump,” which weighs 23g.
* This pump sack is not compatible with the ASP-R7 valve.
○ Includes two large repair sheets, each measuring 5 cm on one side
The ASP-R5 comes with two large square TPU repair sheets, each measuring 5 cm on a side. They cover most types of damage caused by punctures and cuts that can occur in outdoor environments.
■Technical Spec
・Dimensions: 183 x 51 x 9.5 cm
・Stored Size：直径10 x 22 cm
・Body weight：370g
・Material: 20D Nylon
・R-value：5.6
・Accessory：Pump sack / Staff sack / Repair sheet
■Close-up detail
・The “Mummy” model is designed with weight reduction in mind, featuring a tapered fit around the head and below the knees.
・We redesigned the valve’s size, shape, and hardness to make it easier to inflate. In particular, we improved usability during cold weather.
・The Pump Sack is designed with ease of inflation in mind. If you're looking for a lightweight option, please consider the "Airpump."
*Please note that the actual color of the product may differ from what is shown here due to your monitor settings, room lighting, and other factors.
*The average dimensions listed in this text are based on arata's research.
*Please note that since we are using manufacturer images, the actual product may differ slightly in terms of specifications (such as logo placement, color, and pattern placement).
■Excerpt from the manufacturer's description
Taking the balance of lightness and warmth to the next level
All-Season Air Pad ASP-R5 Series
Rated for -20°C; 9.5 cm thick
An all-season air pad suitable for most situations
The R5-class air pad can be used in Japan even during the harsh winter months at altitudes of around 2,000 meters, and since it is suitable for most regions, seasons, and environments around the world, it is an extremely versatile item.
As a result, various companies offer products designed to meet these needs, but the ASP-R5 stands out among them by achieving the highest level of balance between weight, R-value, and durability, all while remaining reasonably priced.
We’ve also taken care to ensure you can choose the mat that best suits your body type and lifestyle.
The "Regular" style: a spacious rectangular design
"Mummy"—designed to fit the human body, with unnecessary parts removed to achieve a lightweight finish
"Regular Short" is ideal for petite people or those who are tall but don't need their heads covered.
The “Regular Extra Short” is perfect for users who prefer a shorter length from head to toe, as well as for carrying as a spare tire for group hikes.
We offer a total of four sizes.
The ASP-R5 is the perfect choice for first-time air mat buyers and those looking to switch from older-generation air pads to a lighter option.
■Technical Note
○ Achieving a higher level of balance between R-value and weight while ensuring a comfortable sleeping experience
The development goal for the ASP-R7 was to ensure thermal insulation capable of withstanding temperatures as low as -30°C; however, it became clear that the structure adopted for the R7 did not achieve the optimal balance between weight and R-value. Therefore, the next goal was to achieve the highest possible balance between weight and R-value.
Although the ASP-R5 and R8 use the same air pad as the ASP-R7, their internal structures are completely different. The cross-sectional structure is very simple: a PET film with a heat-reflective coating is sandwiched between the top and bottom fabrics, reflecting heat rays while preventing convection of the internal air. The ASP-R5 features two layers of this film. While simple, this design is highly efficient and currently offers the best balance between weight and R-value.
For the ASP-R5 and R8, we have designed these models using this structure, paying close attention to every detail of the internal dimensions to ensure the highest levels of comfort, weight, and pressure resistance.
○ Top-tier performance—both in terms of specifications and beyond—: The Pursuit of Pressure Resistance
As mentioned earlier, in the development of the ASP-R5, we are striving to achieve the highest possible balance between weight and R-value—as reflected in the specifications—while also pursuing performance characteristics that go beyond the specifications.
When it comes to air pads, if you focus solely on weight and R-value, it’s easy to create a product that’s ultra-lightweight and has a high R-value. However, if you prioritize those factors alone, comfort and pressure resistance will suffer.
While pressure resistance is not something that the average user typically thinks about, manufacturing plants that produce hundreds of thousands or even millions of units annually and receive feedback from the market know that this is the most common issue and that it is a performance characteristic that should be prioritized over tear strength.
The ASP-R5 and R8 were developed with a particular focus on pressure resistance, in addition to comfort. Regarding their structure, we determined the specific design details by actually testing our own previous development samples, various products on the market, and development samples from our manufacturing plants. While we won’t reveal the design philosophy in detail, the products were designed based on surprisingly detailed calculations, and we have verified their effectiveness.
○ Choosing the right materials was the most challenging part of achieving our goal
Surprisingly, the biggest challenge in developing the ASP-R5 was the most basic fabric.
There is little point in using high-cost materials on par with the world’s finest products and achieving equivalent performance at an equivalent cost. At the start of development, there was no fabric that met the cost requirements in addition to tear strength, weight, and weld strength.
Although it was a very tedious and time-consuming process, advances in coating technology and improvements in quality control at our manufacturing plant have enabled us to produce products using materials that meet the requirements.
They are inflated to a pressure more than three times that of standard automotive tires, held at that pressure for a set period, and then completely deflated. The ASP-R5 and R8 are lightweight, yet have been confirmed to maintain their functionality even after thousands of repetitions of this rigorous cycle.
○ A mummy-style sleeping bag that prioritizes comfort and does not prioritize excessive weight reduction
We also offer a mummy-style model for users seeking a lightweight option, though we have not prioritized excessive weight reduction. The overall width is set at 51 cm—a standard measurement for mummy-style sleeping bags—with a simple semicircular shape around the head and a gentle taper from the knees down. This design balances weight reduction with a fit that helps prevent the sleeper from slipping out of the sleeping bag.
○ Simple Pump Sack
The pump sacks for the ASP-R5 and R8 are designed to seal more easily around the air intake, making it easier to transfer the air from the pump sack into the pad without letting any air escape. They weigh approximately 80g.
If weight is a concern, we recommend purchasing the “Airpump,” which weighs 23g.
* This pump sack is not compatible with the ASP-R7 valve.
○ Includes two large repair sheets, each measuring 5 cm on one side
The ASP-R5 comes with two large square TPU repair sheets, each measuring 5 cm on a side. They cover most types of damage caused by punctures and cuts that can occur in outdoor environments.
■Technical Spec
・Dimensions: 183 x 51 x 9.5 cm
・Stored Size：直径10 x 22 cm
・Body weight：370g
・Material: 20D Nylon
・R-value：5.6
・Accessory：Pump sack / Staff sack / Repair sheet
■Close-up detail
・The “Mummy” model is designed with weight reduction in mind, featuring a tapered fit around the head and below the knees.
・We redesigned the valve’s size, shape, and hardness to make it easier to inflate. In particular, we improved usability during cold weather.
・The Pump Sack is designed with ease of inflation in mind. If you're looking for a lightweight option, please consider the "Airpump."
*Please note that the actual color of the product may differ from what is shown here due to your monitor settings, room lighting, and other factors.
*The average dimensions listed in this text are based on arata's research.
*Please note that since we are using manufacturer images, the actual product may differ slightly in terms of specifications (such as logo placement, color, and pattern placement).
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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 unavoidably during the manufacturing process.
・Depending on the material of the product, there may be variations in color, texture, or pattern from item to item.
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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 the item may be out of stock in some cases. We apologize for any inconvenience this may cause and will notify you via email if this occurs. Thank you for your understanding.