Race cycling helmet time trial helmet suitable for men sizes 50 56 cm 54 60 cm 56 62 cm us sizes s m l main colour white number of air vents 5 safety features reflective print size adjustments wheel adjustment system headring features enhanced protection for back of head constructions in mold microshell outer material polycarbonate weight 210 g inner material polystyrene eps marks of approval asnzs 2063 cpsc en din 1078