When conditions harden on a long climbing day and a shell goes on over the top, the Switch Pant is the insulated pant that keeps working underneath. Its Octayarn warp-knit lining traps warmth, moves moisture off the skin, and dries fast, so the light insulation keeps pace with a high work rate. The wind-resistant 20D nylon outer stretches with the legs, and its water-repellent finish sheds rain and snow. What Our Gearhead(R) Experts Are Saying:"On long cold approaches, I wore the Switch Pant on its own at a hard pace. The legs stayed warm in the wind, and the lining breathed as the heat built. I added a shell only once the climbing started."