The workhorse of Craft"s cool weather baselayer system. It works on one simple principle: Drier skin = warmer body. Craft proZERO fabric is the core of their layering system. It adheres to your body like a second skin thanks to its Air Rib construction that allows warm body heat to escape before it signals the body to sweat. 100% polyester textured filament yarns stay in touch with your skin, leading moisture away from your body. The interlocking knit can stretch up to 300% of its length and the entire torso is seamless, so you know that no other base layer fits as beautifully. Craft"s proZERO fabric has been tested and recommended by Gore for use with the Gore Tex fabric outerwear. Best used in temperatures 60 degrees and below. Available in Black in sizes Small through XX-Large. Product FeaturesMaterial: Insulation Weight: lightweightFit: fittedLength: Center Back Length: Pockets: Antimicrobial: SPF Rating: UPF Rating: Thumbholes: Weight: Recommended Use: layering, training, racing in cool weatherManufacturer Warranty: