Arcteryx Fission LT Pant The low profile Arcteryx Fission LT Pants provides all of the necessary weather protection and comfort you need for cold weather adventures. The WindStopper shell keeps the blustery wind and moisture out, while PrimaLoft insulation in teh Fission LT provides warmth and comfort. Arcteryx reinforces the knees and seat, so that the Fission LT pant will give you season after season of durable use. The Fission LT Pant is the smart way to protect yourself during cold weather activities. Features: Adjustable waist 220NR WindStopper loft, 340P WindStopper loft Cuff drawcord Full separating side zips Front 'belay' fly Reinforced seat and knee WINDSTOPPER® Dryloft Primaloft® Sport Insulation