The DMM Ultra O is a classic climbing carabiner trusted by professionals and amateurs around the world. Now the Ultra O has been coupled with DMMs patented Durolock design to provide a safe and easy quadruple-action auto-locking ability to minimize the chances of accidental gate opening and maximize security. Sophisticated yet functional, the gate is operable with one hand. The oval shape of the Ultra O facilitates multiple connections and the round basket allows any of the connections to self-center when weighted.