The Mammut Sender Moc Low (out Oct 8, per Mammut) is a buy as the shoe you change into after the descent and on the way to and from the mountain. Mammut lists it at ¥23,100 and 320g (UK 8.5), a lace-free insulated moc. Mammut says it's for "scenes other than the trail," so I don't recommend it as a shoe for walking mountain paths.
The Gear Nerd's Pick
Beyond the insulation, this shoe puts a heat-reflecting film in the board that joins the upper to the sole. The idea is to send heat escaping from the sole back into the shoe, which helps in the time you spend standing instead of walking. That's why I count it as a shoe to rest your feet in after you take off your hiking boots, not a shoe for walking.
Key points
- Price per gram is ¥72.2 (¥23,100 ÷ 320g). At the regular price of the Nuptse Bootie Waterproof VII Short it's ¥62.3
- 80g lighter per shoe than the No. 1 hiking boot in our rankings (Sirio P.F.156-3, about 400g)
- No waterproof membrane is listed, only a water-repellent finish. Mammut's stated uses are cooling down after hiking, winter in town, and getting to the mountains
The Sender Moc Low comes out Oct 8. A shoe to change into, not a replacement for hiking boots
After you come down and take off your hiking boots, which shoe do your feet go into for the ride home by car or train? The Sender Moc Low is a shoe for that moment. Mammut describes it as "designed with scenes other than the trail in mind." The series, too, falls under the town-oriented URBANEERING line.
The scenes it expects are four: cooling down after a hike, getting around town in winter, traveling to the mountains in fall and winter, and trips away from home. This article looks at price and weight within that range.
How I judged it
The first things I looked at were the stated use and the weight. At 320g (UK 8.5), it's 80g lighter per shoe than the No. 1 hiking boot in our rankings. Next I compared it against The North Face Nuptse Bootie, another insulated winter shoe: it's 65g lighter but costs about ¥10 more per gram. What gave me pause is whether to pay ¥23,100 for a shoe with no waterproof membrane listed. Still, I recommend it, because you can slip it on without laces and it even has a film that returns heat above the sole. It suits anyone who commutes to winter mountains by train or car and doesn't want cold feet after the descent.
Image: Rakuten Ichiba
Mammut Sender Moc Low (men's)
Lowest price on Rakuten: ¥19,599 (as of 10/14). Prices vary by shop, up to ¥23,100, and change daily.
RecommendedSee it on RakutenSee it on Yahoo! Shopping JapanSender Moc Low weight and price: what's in the insulation
| Item | Official listing |
|---|---|
| Official price | ¥23,100 |
| Weight | 320g (UK 8.5) |
| Insulation | Mammut LOOPINSULATION (50% rope offcuts, 50% recycled plastic) |
| Lining | Microfleece |
| Protection from water | PFC-free water-repellent finish |
| Outsole | Mammut Swiss Design Winter Compound |
| Sizes | UK 6.5 to 11.5 (25.0 to 30.0cm in the size chart) |
The page also lists an "insulation value (EN ISO 20334): -5." But it gives no unit and no explanation of what the number represents. I don't use this number as a guide to "how low a temperature you can wear them in."
A heat-returning film sits above the sole
Here I'll gush. The value of this shoe lies in the underside of the foot more than in the insulation. According to Mammut's feature page, the board that joins the upper to the sole (the strobel board) holds a heat-reflecting film that sends heat from your foot back into the shoe.
It doesn't only wrap the top of the foot in insulation; it adds a layer on the underside too, close to the ground. My read is that it's built for the time you spend changing in a parking lot or standing on a station platform.
Weight compared with the Nuptse Bootie and hiking boots
| Model | Weight | Official price | Per gram |
|---|---|---|---|
| Mammut Sender Moc Low | 320g (UK 8.5) | ¥23,100 | ¥72.2 |
| The North Face Nuptse Bootie WP VII Short | About 385g (9 inch, per shoe) | ¥23,980 | ¥62.3 |
| Sirio P.F.156-3 (hiking boot) | About 400g (26.0cm, per shoe) | ¥20,350 | ¥50.9 |
65g lighter than the Nuptse Bootie, with no waterproof membrane
385g − 320g = 65g. The price difference is ¥880. The big difference is protection from water: the Nuptse has a waterproof membrane called Tech Proof, while the Sender Moc Low stops at a water-repellent finish. If you often walk through slush puddles, the Nuptse's build fits better. For the record, this Nuptse model was listed as outlet today on the official store, at ¥16,786.
Image: Rakuten Ichiba
The North Face Nuptse Bootie Waterproof VII Short
Lowest price on Rakuten: ¥15,590 (as of 10/14). Prices vary by shop, up to ¥23,980, and change daily.
RecommendedSee it on RakutenSee it on Yahoo! Shopping Japan80g lighter per shoe than a hiking boot. But not a shoe for mountain trails
400g − 320g = 80g. On weight alone you might want to wear it in the mountains, but it's a moc that can't be cinched with laces. For a shoe to walk mountain paths, choose from the hiking boot rankings.
Image: Rakuten Ichiba
Sirio P.F.156-3
Lowest price on Rakuten: ¥18,200 (as of 10/13). Prices vary by shop, up to ¥20,350, and change daily. The surest way to try boots is in the evening, when feet swell, wearing your usual socks. Fit varies by brand, so check the shop's return and exchange terms before buying.
RecommendedSee it on RakutenSee it on Yahoo! Shopping JapanIf you take it to the tent site or a hut, that's 640g in your pack
The page doesn't mention tent sites or mountain huts. Whether to carry it is a call you make by weight. If 320g is per shoe, a pair is 320g × 2 = 640g, a load heavier than one 500ml bottle of water. For the weight of a tent, the main item in a backpacking load, see the lightweight solo mountain tent rankings.
The weak spot: it's heavy as a change of shoes to carry up. The use that fits best is leaving it in the car or at the lodge and putting your feet into it after the descent.
How does the Sender Moc Low fit? What to watch for
The first is water. No waterproof membrane is listed, so it isn't a shoe for walking long distances in wet snow. The outsole advertises grip on frozen paths and slippery terrain, but its target is still town and travel.
The second is size. It's sold in UK sizes and can't be adjusted with laces. In Mammut's size chart UK 8.5 is 27.0cm, and each half size changes by 0.5cm. To pick the size, match the cm of the shoes you own to Mammut's size chart.
The women's model has a different number (3030-05790) at the same ¥23,100, and weighs 280g (UK 5.5).
Image: Rakuten Ichiba
Mammut Sender Moc Low (women's)
Lowest price on Rakuten: ¥29,600 (as of 10/14). Prices change daily.
RecommendedSee it on RakutenSee it on Yahoo! Shopping JapanWho is it for?
It suits someone who wants a warm shoe to change into from hiking boots at a mountain hut or tent site. Mammut's category is "other than the trail."
If you'll walk long distances in snow or rain, a shoe with a waterproof membrane is another way to go. If you carry it, 640g is on the heavy side.
FAQ
When does the Sender Moc Low come out?
According to Mammut, it came out Oct 8, 2026. The men's price is ¥23,100 (incl. tax).
How much does the Sender Moc Low weigh?
Mammut lists the men's at 320g (UK 8.5) and the women's at 280g (UK 5.5). This article compares them as per-shoe numbers.
Is the Sender Moc Low waterproof?
It's listed with a PFC-free durable water-repellent finish. For days spent walking long distances in wet snow, the Nuptse Bootie with a waterproof membrane is a better fit.
How do I pick the size of the Sender Moc?
Convert UK sizes to cm using Mammut's size chart. Men's run from UK 6.5 (25.0cm) to UK 11.5 (30.0cm) in half-size steps.
