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Review: NEMO Tenser Alpine A sleeping mat suitable for four seasons, with a total of three characteristics: insulation, comfort and weight, and a sleeping mat that is perfect for the entire triple season.

written by Outdoor Gearzine Editorial Department

The "cold" is not something you'll ever think about when staying in a tent in late spring, summer, or early autumn. However, the coming season will be dangerous and critical if the equipment and weather and temperatures are not matched. If you're in the mood, you might be able to get through it by increasing your exercise even if it's a little cold, but that's not the case with sleep, which is the coldest night to the early morning. You will end up sleeping trembling shaking, and if you're not good enough, you may end up sleeping. When you lose sleep, it affects your behavior the next day, and it can even lead to life and death issues, especially in long-term hiking.

Bedding is such an important tool, but not only the sleeping bag but also the mat underneath is very important. It's not considered too much of an important factor, but just laying it down will make the heat retention and comfort significantly different. Despite this, there are many different types of mats in the world that suit different temperatures, and many people may not know which one is what. The Tenser Alpine from NEMO we will be reviewing this time , is a high-spec mattress that you can choose without thinking about the difficulties and expect a more reward than you have chosen. We have reviewed it, including its use at low temperatures that are actually likely to be used.

The rough features of Tenser Alpine

NEMO 's Tenser Alpine , ranging -29°C to -23°C , making it a lightweight, quiet, and comfortable air mattress. To make it lightweight, the surface fabric 20D polyester , which also contributes to the compact storage. The interior is equipped with insulation in a unique three- layer structure, blocking out cold air from the ground, while keeping the body heat generated efficiently and ensuring heat retention and comfort. By using a valve system that uses pump sacks, which are becoming standard for air mats, it is now possible to set up and take out quickly, and fine adjustments to the air volume have been simplified. 8cm thick , and is a highly balanced model that covers all the requirements required for an air mat. Short sizes (S) and regular sizes (R) are available depending on the purpose.

Recommended points

  • Lightweight and compact
  • High insulation and heat retention
  • Easy to set up and take out
  • Quietness

Points that interest me

  • The front and back are slippery
  • Durability

Main Specifications and ratings

itemSpecifications and ratings
colororange
sizeS: 122 x 51cm
R: 183 x 51cm
Storage sizeS: 7 x 20cm
R: 8 x 20cm
Matte thickness8.0cm
Official weight
(main unit only)
S: 307g
R: 475g
Actual measured weightR: 473 + 16g storage bag + 62g pump + strap
Surface material20 denier polyester
Reference temperature−29℃ 〜 −23℃
R valueprivate
Insulation materialThermal Mirror™ metalized film
accessories
  • Staff sack (storage bag) 
  • Vortex Pump Sack
  • Velcro strap
  • Repair Kit
Comfort★★★★★
Ease of setup and removal★★★★☆
Thermal insulation★★★★★
weight★★★★☆
Storageability★★★★☆
Versatility★★★★☆
comprehensive evaluation★★★★★

Detailed review

Insulation and insulation thanks to its unique structure

The R value of NEMO mattresses is not disclosed, so we cannot compare it with other manufacturers based on the R value, but the manufacturer's recommended operating temperature is -29°C to -23°C, which is now available in Japan anytime all year round. Perhaps to reduce weight, the surface is made of 20D thin polyester, but the interior is designed to be able to be used without any problems even in harsh winters by placing three films called Thermal Mirror™ Metalized Film, which is made of aluminum vapor deposited, suppressing the convection of cold air from the ground, increasing insulation, and reflecting heat from the body.

alpine

Looking inside through the valve, you cannot see the solid structure, but you can see that the metal film is folded and overlapped intricately.

The mat itself uses NEMO's unique structure called the Space Frame™ baffle structure, which prevents the bottom from reaching even when load is concentrated locally. Even though the excellent internal structure provides excellent insulation and heat retention, if the bottom reaches when you place your elbows or other surfaces, you will be able to feel the heat directly from the ground, and the warm air that has been kept warm will escape, making it a must-have structure for mattresses that are used in harsh environments.

The cushion thickness is 8cm, which is quite voluminous, providing ample cushioning. In addition, the above-mentioned space frame baffle structure prevents the bottoming, and the thickness is maintained on the periphery to maintain balance when moving left and right, making the cushion feel very comfortable, and we focus on not only cold resistance but also comfort, achieving this at a high level.

The mat thickness is 8.0cm. It's quite a volume.

Valve system finally adopted by NEMO

NEMO uses a new valve system and pump sack from this model. As expected, the overwhelming speed and comfort of setting up and retracting have been greatly improved.

The included pump is made from the same material as the main body. An instruction manual is printed on the front, in English.

Up until now, fine adjustments were easy to adjust for valves once they had been inflated, but it was a pain to inflate them. And it took a while to completely deflate the air when it was removed. This model is especially popular at high altitudes, so the fact that there is no need to send air at high altitudes, which is a heavy work, is highly rated. The valve system makes it easy to fine-tune the air volume.

Press the center of the valve to slowly eject the air, allowing you to fine-tune the amount of air inside.

Also, this valve system is flat against the mat surface, so you won't have to worry about it when sleeping or storing it. This must have been a long-awaited experience for NEMO users.

The new valve system is completely flat so you won't have to worry about sleeping or tidying up.

Impressions of actually using it

This time, considering that it would be used in winter, I tried using it in two environments, with temperatures around 1°C and around 20°C. First of all, the insulation and heat retention are extremely high, and when I changed position in the morning, when the outside temperature was about 1°C, I moved my head, and the parts that had not been in contact with my body were cold and involuntarily cold! I muttered, but the side I was in contact with was so warm. At this temperature, no heat was transmitted from the ground. It reminds me of the incredible heat that comes out of my body. Conversely, in an environment of around 20°C, when you sleep, it gradually gets warmer and you start to sweat. You may find it comfortable to use in autumn, winter, and spring. It seems to be useful in alpine mountains in the summer.

As expected from 8cm thick, the cushioning is high and comfortable. However, rather than being soft and comfortable, it is a moderate resilience and sleep-like feel like a high-resilience mattress, and there is no unpleasant feeling at all. Models that use metal films can be used to make sleeping comfort even when they move, as the rustling and the film rubbing against each other, but this Tenser Alpine was not at all and was comfortable. However, although it does not reach the ground when you touch your elbows or something, it sinks into the mat and the balance of the air inside the sinking mat is quite different. It doesn't seem to be suitable for sleeping while lying down. Both the front and back are not anti-slip, so if you use it on a slightly slanted area, it will slip quite a bit. In fact, when I slept at a slightly diagonal place, I suddenly woke up and my feet were protruding from the mat. When crawling up, putting weight locally on the body will cause your balance to become unbalanced, so when you're sleepy, that was quite a hassle.

NEMO is the first to use a valve system that uses a pump to inflate it. First of all, it's good to have the valve flat. Previous valves have been pop-out and I tend to be a bit concerned when storing or sleeping, so this will allow you to sleep without worrying about anything.

The valve is double-layered with a lid and check valve, so when inflation or adjusting the amount of air, a check valve is attached. By connecting the included pump, it can be inflated in about three times, and you can easily fine-tune the air volume. I also tried Sea to Summit, and this one was packed with just two sessions, so it was a bit more effort than that, but considering that I had been using it myself, it was an overwhelming amount of effort! When retracting, remove all the valves to air out in an instant. If you take it off while you're sleeping, it's just a moment.

Once you remove the lid, the evacuation will be instantaneous.

The weight is 473g, a regular size (R) we reviewed this time, and is extremely light compared to the sleeping mats from other manufacturers, which have the same level of functionality, and the storage size is 8cm x 20cm, about a size larger than a 500ml can. There are other mats with similar functionality and weight, but as the price is expensive, this NEMO Tenser Alpine is one of the best of the same mats.

The storage size is very compact. It is about a size larger than a 500ml can and is almost the same thickness.

However, to achieve lightweight and compactness, 20D polyester is used. As you can see from the actual use, the fabric is thin, so you may be worried about its durability. It is best to bring a repair kit with you when traveling for long periods of time. If there's one more thing, it's a pump. The main unit weighs 473g, while the pump weighs over 60g. Of course, a pump is very convenient, but it's not an essential one either. In contrast, Sea to Summit is also suitable for both storage bags and dry sacks. They must be making a lot of effort to reduce the weight, so if they try again, it seems that the UL-oriented hikers who are concerned about weight will also be able to move more.

The pump is thin so it can be stored with the main unit.

Summary: Recommended for people like this

It is suitable for up to -30°C, but is lightweight enough to weigh less than 500g even when you put a stuff sack in it, and although it is thick, it is not strangely fluffy and has a high stability, and has no sacrificing comfort. The back is warm enough in spring and autumn, not only in the middle of winter, but also in spring and autumn, so if you use a lightweight sleeping bag, it may be a useful tool to make it lighter. With so many insulation and insulation specs, it's hard to decide whether to use it in the summer, but it feels warm and stuffy in low mountains, but it looks like it's a comfortable sleep in high mountains.

I just want something light and comfortable to use even in the middle of winter! This is the perfect model for such a selfish hiker. It achieves both the most essential requirements for mats: comfort and heat retention. For those who hike for a long period of time, the choice of bedding, especially the balance between weight and heat retention and comfort is extremely important. Those considering a mattress of the same level are highly functional and cost-effective, so you won't be able to regret buying it.

Another major point is that it can now be inflated with a pump. There must have been a lot of people who like NEMO mats but don't have a pump design. Tencer Alpine is a four-season mattress that attracts users. It may be a high-spec mattress that is currently open to no enemies.

created by Rinker
Nemo Implementation (NEMO)
¥37,019 (As of 2025/08/07 11:53:30, according to Amazon - details)