Carabiner Oz. Black Diamond CARABINER OZ is designed with an optimized shape and the snag-free benefits of their HoodWire Technology.. The 30 ml (1 oz.), hot-forged Black Diamond OZ is still the best way to lighten your rack. A patent-pending stainless steel wire hood brings keylock functionality to wiregate carabiners without losing the lightweight and anti-freezing benefits. And thanks to the OZ's new geometry, it holds strong as the lightest carabiner in Black Diamond’s line.