As bikes become more capable and trail riding gets faster riders need a new generation of helmet. The M2 represents the latest in open face protection. Its Conehead(TM) technology uses dual density foam to dissipate impacts more effectively, giving you a safer ride. The M2 offers full rear head coverage and is tested beyond CE, CPSC, and AS standards. A rapid adjust chin strap and one-hand dial adjustment make it easy to get the right fit, and the custom liner is easily removed for cleaning. A total of 19 vents provide airflow to keep you cool on the trail. Features: - Open face all mountain design - 19 vents - ConeHead(TM) Technology with dual density foams in impact absorbing zones - Full rear head coverage - Custom 7iDP liner for superior fit and comfort - Custom 7iDP adjustable visor - One hand dial fit adjustment - Rapid adjust chin strap - Complies with CE, CPSC, AS standards Sizing: - XS/S: 20.5 - 21.75" / 52 - 55cm - M/L: 22 - 23.25" / 56 -59cm - XL/2XL: 23.75 - 25" / 60 - 63cm