Montbell mont-bell 1106530 Clima Air Vest Women's S size Ivory This vest uses Clima Air, which is lightweight yet highly insulating, and performs well as a mid-layer. It features an active design with stretch material on the sides. It's exceptionally easy to move in, providing comfortable wear even during high-activity activities. Material Feature: "Clima Air" This is a fleece material made by loosely knitting long-pile polyester fibers. The loose knit reduces the amount of fiber, achieving weight reduction. The long-pile high-loft structure can store a large amount of air, allowing for maximum heat retention with minimal weight.