Race cycling helmet suitable for men sizes 51 55 cm 55 59 cm 59 63 cm us sizes s m l main colour black secondary colour yellow number of air vents 19 safety features flashy colour neon inner padding antibacterial size adjustment wheel adjustment system construction in mold outer material polycarbonate weight 234 g inner material polystyrene eps helmet technologies giro roc loc air giro x static padding giro wind tunnel ventilation