Their most versatile insulation piece, the Montane Prism Jacket is an essential piece of mountain clothing whether you're actually headed to the mountains or not. Made using 40g PrimaLoft® SILVER ECO insulation throughout, inside a windproof, water-repelling PERTEX® Microlight Mini Rip-stop outer shlel, it's warm and weatherproof yet lightweight enough to be worn on the move.