Featuring a built-in intelligent cooling system that works with your body temperature, this premium lightweight baselayer is ideal for outdoor work like construction, gardening and farming. It's also a smart choice to wear hiking or camping. Rebar Evolution Athletic Fit T-Shirt Product Features : 0 : ClimateTEK™ dynamically responds to your body temperature to keep you cool when things heat upGreater Arm Mobility™ lets you move freelyFreshTEK™ sustainable odor-resistance, 1 : Chest pocket Men's Rebar Evolution Athletic Fit T-Shirt in Black, Size: Medium by Ariat