Our Atomic Treeline 2L Pant M is insulated to keep you warm. With Pertex flex material and a brushed tricot lining to keep you comfortable. But unlike other insulated pants on the market, it is also really light thanks to its low-bulk PrimaLoft insulation. It also features warm Thermaflect lining in strategic areas where you’re most vulnerable to the cold. The perfect pant for all-day all-mountain skiing.