Large D shape for great handling, huge gate opening and massive strength! At a rated strength of 72kN, it's one of the strongest carabiners in the world! Heat-treated, half-load tested (over 8000lbf) and built to exacting standards, the 1/2" Large D is one very fine steel carabiner. Meets NFPA 1983.01 standards UL Classification G. Made in USA.