Coolbase Technology keeps players cool and comfortable Zip-off sleeves provide two looks Moisture wicking and water repellant fabric keeps you dry 100% polyester featuress durability-machine washable Description Convertible sleeves provide you with long and short sleeve options depending on weather. Features water repellent material. 1/4-zip functionality. Cool Base technology provides moisture management and temperature control, keeping you cool, dry, and comfortable all day long. 100% polyester.