The Half Dome has long been a staple for climbers worldwide. Now redesigned, the helmet features a new lower-profile suspension system with a one-handed dial combined with streamlined headlamp clips for added comfort and simplicity. Finally, an updated chin strap adds more efficiency and security while you're on the rock.. . Co-molded EPA foam with a low-profile polycarbonate shell. Updated, low-profile suspension system. Streamlined, lightweight headlamp clips. One-handed fit adjustment dial. Easily adjustable chin strap. Size Range: . . S/M: 19.7-23 in. (50-58cm). M/L: 22-25 in. (56-63cm). . Weight:. . S/M: 11.6 oz. (330g). M/L: 12.3 oz. (350g). . Spot clean. Imported.