Black Diamond Half Dome Helmet Synthetic The Half Dome is an all-purpose workhorse ideal for everything from trad cragging to alpine expeditions. A custom-designed wheel adjuster for quick, secure and precise adjustments. Hybrid design with molded EPS foam, generous ventilation and highly adjustable suspension system. Suspension's custom wheel adjuster allows for improved fine-tuning of fit. Headlamp clips are the most secure headlamp attachments on the market. The most durable helmet Black Diamond makes. Weight : S/M - 10 oz. M/L - 11 oz.. S/M Fits 48-57 cm (19-22.5 in.). M/L Fits 55-61.5 cm (22-24 in.).