FABRIC Performance Polyester SWEATBAND Stay-Dri Performance Stretch MATERIAL 98% Polyester, 2% Spandex VISOR Precurved SHAPE Mid-Pro This Referee cap is built with Richardson PULSE fabric with R-ACTIVE tech. It's designed to keep you cool, dry and comfortable on the field, so you can focus on the game. R-FLEX sizing offers fit for Referees at all levels of officiating.