Troy Lee Designs Drone A1 Adult Bike Sports BMX Helmet - Army/Green / Medium/Large Reinforced polycarbonate shell in-molded with the EPS liner extends down the sides and back of the head for maximum durability 8 pressurized intake passages draw in cool air for maximum ventilation 8 rear vacuum vortex outlets help exhaust and draw heat from head Triple position adjustable retention system allows customized fit for various eyewear, head shape and riding styles DOT approved. Meets the FMVSS 218 Standard