This performance vest with 2XU’s 8/10 hydrophilic membrane with waterproofness of 8,000mm H20 will keep you warm and dry. Coupled with a moisture vapour release (10,000gm/24hr) specifically designed to allow moisture escape when working out. Fleece backing, hydrophilic membrane and polyester outer make this 3 layer fabric a key ingredient in the jacket and Velo-Pro side and back panels enhance the warmth with minimum bulk.