MIPS Technology - Multi Directional Impact Protection System . APB - Aramid Penetration Barrier maintains lightweight attribute while improving protection . VDSAP - Ventilated Double Shell Anti-Penetration system for improved ventilation . Multi-impact EPP liner . Removable goggle clip. Detachable ear pads and neckroll . Compatible with communication neckroll . Certified EN 1077-B, ASTM 2040 . Size S = 53-54cm . Size M = 55-56cm . Size L = 57-58cm