Intake and exhaust ports ensure plenty of ventilation to keep you cool ABS ears are firmly fixed to the body of the helmet Quick release buckle system, provide perfect protection. Specification: Shell material: Qulaity ABS Liner material: 100% Polyester. Size: S M L XL XXL. 1 x Motorcycle Helmet with bluetooth or not, if you choose bluetooth, bluetooth will come, if you don't choose bluetooth, then it won't be included, please note.