The North Face Summit L4 LT Soft Shell Pant
The pant for the Proprius system is specifically built for high-output ski-touring missions. The lightweight, four-way stretch soft shell material is super breathable and moves with you whether on the skin track or boot pack. For spring days or when you're really getting after it, the 10" side vent zips help dump heat to keep you dry. The thigh pocket has a built in beacon loop, which we are proponents of. One, a chest harness has to be removed to ditch a layer. Secondly, it's right there when you need it and second matter.
The cut is athletic and form fitting. This keeps the breathable material close to you and out of the way of crampons when the spikes come in to play. Keprotec reinforced kickpatches protect the inside of the lower leg from said crampons as well as running while skinning. The small cuff can be opened to a bigger boot with an 8" zip and adjustable snap closure. The fit is best with a ski mountaineering boot.
For those of us that move fast and light, the entire Proprius line is awesome, and the pants are perhaps the "fastest" item in the system
Average Weight: 470 g (16.5 oz)
Fabrics: 70D x 140D 225 g/m2 WindWall®‚74% nylon, 15% polyester, 11% elastane stretch double weave
The reasons I like the TNF Proprius Pant are that the fabric seems to have the right level of air permeability for both cold wind and warm still air. There is a balance, and I think the Proprius has achieved it. The pants have a pocket on the right thigh for snacks, sunglasses, or glove liners or two of the afore-mentioned, but not more. It is too bad that they did not include another pocket on the left thigh. Other advantages not to be over-looked are the ski-boot-compatibility with the edge protection patches and the leg opening zipper that allows you to go over a boot cuff. The webbing belt has a generally secure attachement and is infinitely adjustable not matter how much weight you lose going uphill!