Nuclei Pant Men's

It's about time I started packing extra insulating layers for my legs! We're great at bringing spare upper body layers, but the pants have been something I have neglected. Now that I have these Proton Pants, I am more prepared, and more comfortable. The full length zippers make it next to effortless to put on or take off, even with crampons or ski boots.

Saving myself always when it gets nasty on the mountain.

These are awesome, very warm insulated pants. I’ve never been cold enough that I needed them doing an activity but I’ve taken them on expeditions to the Himalaya, Waddington, and Canadian Rockies where they’ve been critical in camp and at night. Full zip makes them easy on/off and sizing seems normal.

These pants are very warm for the weight. There is reinforcement in high wear areas to give extra durability while still being packable. The fact they can pack into their own pocket (with a carabiner loop) is a huge space saver in your pack. The zipper works great when you are putting them on while wearing crampons. Much easier than other brands I have tried. The only con is the fact they only zip up from the bottom but it is a sacrifice I am willing to make. Maybe the next generation will include this and they will be perfect. These pants literally saved my behind when I was climbing in -25F (-30C) and starting my decent. My legs were getting cold and started losing sensation in my hips. As soon as I put these on, my legs were toasty warm. IMHO these are the best value for fit, warmth, weight, packability, and durability out there. I wear a large and large fit perfectly over my other layers.

As a paraplegic I use these pants daily for commuting to and from work on my Bowhead bike year round. They are compact enough to keep on under shell pants for the entire work day keeping you toasty for the ride home.

I am happy with this very light and warm pant, especially for protection purposes, cold and windy conditions

I've tried a few different pairs of pants similar to these and owned similar items from BD and WM and these are the closest to ideal that I've found so far. If you buy your normal size, the fit is oversized feeling but clearly intentionally so, so I'm down with it—get to that later—and the knee, butt, and inner ankle reinforcement make them practical as working pants for belay and not just for the tent. I noticed another review on here stating the wish for double zippers or zip down from the top, but I love the design and find it ingenious. Zipping open from the bottom allows for a partial unzip to get the pants on even with mountaineering boots (potentially crampons if you're brave, haven't tried it) due to the specific fit of the top sections of the legs and the generously wide opening at the waist, which is accounted for by a toggle cinch waist closure (this toggle is the only aspect that I feel could be improved about the pants — wish it ended up feeling more 'lay-flat' against your waist instead of being so noticeably protruding under heavier upper layers). To the other reviewers point, you definitely have to pull the pants down to squat instead of unzipping but I appreciate the simplicity of the system more than I see it as a hassle, personally. Really happy to be into a pair of belay pants finally. Arcteryx always A+ design work thank you guys.

Got these pants for winter steelheading, snowshoeing and skiing. Awesome pant so far, been keeping me super warm on cold days. My only recommendation for V2 would be to have a snap or clip around the waist, I find when layering they can bit a bit tight around my legs putting them on.

I wanted an insulated, full zip pant for layering in backcountry and for belaying. First - there are no Womens options so had to order mens (sizing and hip differences matter). When on the XS fit well in length, a little odd to be so high waisted and tight at my small waist - but literally could NOT pull them on unzipped past my knees therefore had to unzip to put on. It was strange and frustrating and confusing…..makes no sense for a pant that should be functional. Secondly - the zipper is only one way. So you have to unzip all the way UP to undo. To close you start at top and zip down. So you’re not getting in to your lower layers or gear unless you bend over and unzip from bottom up! WHAT!? Did the designer ever wear layers or gear or ever have to pee in the woods? This makes no functional sense and compared to every other brand (MH Compressor, BD Belay Pant, and RAB Photon) who ALL have two-way zippers - Arcteryx failed miserably! Why not have the zippers be two way zip from the top to put on and access inside/adjust/pull down if you choose? Material and compressibility is about the only positive of these pants. I won’t even bother ordering a SM to see if it fits a little better - without the two way zipper these pants are a disappointing fail. I expect better from Arc’teryx. I almost exclusively wear Arc’teryx - however the future in their styles/designs and true functionality is being compromised, hence losing brand trust and reliability.

Great Arcteryx quality! Extremely warm and lightweight- perfect for ice climbing. I'm normally a small but needed a medium to fit over winter kit, harness etc. Would give 5 stars if fly was fully separating to five full access to tie in area and, if side zips were perhaps two way. ( really deserves 5 stars though and these are just thoughtful suggestions)

Bought as a winter belay pant for rock and ice, ski traverse camping. I made sure to purchase a size larger to fit over a harness, warm pants to belay with so far.

Used these on a winter backpack, very warm and comfortable Side zippers work great. I kind of wonder if something similar but with active (breathable) insulation would be even better, but these are so easy to add or remove while moving that this is not a problem.

I am continually amazed by how warm and light Arcteryx products are. Did not think they would be but they are very warm. Almost hot. Stretchy in the right spots, great zipper locations, extra durable for how light they are. They fit large for sure.