Coolgear shirts are designed for all seasons (not for Warmth) Find your size on the chart below. If you prefer a looser fit, go up a size. Flat-lock seam It promotes excellent comfort and protection. Early recovery After workout, it will help you get well by controlling blood flow and preventing being swollen. Shield Ultraviolet rays This safeguards your skin from ultraviolet rays by more than 99%(UPF 50+) in the outdoor activities. Deodorization function Deodorization function do not leave us unpleasant smell behind from sweat and dust.