The Rab Men's Xenair Light Insulated Jacket has the versatile warmth necessary for doing just about anything in the mountains. Whether you're winter skiing or summer alpine climbing, the Xenair Light is reliably warm however you prefer playing in the mountains. It features the loftiest, most dependable insulation from Primaloft, and the Pertex Quantum Air shell ensures air-permeable breathability. Unlike standard shells, which only begin to breathe after you start sweating, air-permeable breathability begins breathing the second you zip up.