The Icebreaker Merino 260 Vertex Chillwave Half Zip pairs a warm, 100% Merino build with a zip that opens up the moment a climb or hard push starts generating heat. Gusseted underarms, flatlock seams, and offset shoulder seams keep the fit moving cleanly through repeated motion on snow, and Merino's natural odor resistance means the top holds up trip after trip, not just for one outing. What Our Gearhead(R) Experts Are Saying:"I left the zip cracked the whole way up a long skin track instead of stopping to peel a layer, and sealed it back up the second the wind hit at the ridge. That's the exact moment a half-zip earns its place over a crew."