HMS carabiner with safety mechanism against accidental transverse stresses. Our popular safety carabiner now benefits from improved construction, improved break resistance and reduced weight. It always offers double security, with easy handling. The screw closure can only be used when the Safety Gate is open. Any accidental opening is excluded, as is an unintentional rotation of the carabiner in the harness eyelet. This avoids any risk of dangerous transverse stress. For the Smart 2.0 belay system, Mammut recommends using the Smart HMS 2.0 carabiner.