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 on the rock. Size Range: [S/M] 48-57 cm (19-22.5 in) [M/L] 55-61.5 cm (22-24 in).