Carabiner Gridlock Screwgate. Black Diamond GRID LOCK SCREW GATE CARABINER has a revolutionary, patent-pending design.. It was made possible by Black Diamond’s in-house hot forge, which eliminates the dangers of cross-loading. Designed specifically for belaying, the intuitive, easy-to-use GRID LOCK isolates the belay loop behind its uniquely shaped gate, thereby keeping the carabiner in its proper orientation. The GRIDLOCK's I-beam spine transitions into a large, rounded rope-bearing surface for maximum strength and smooth rope feeding. Simply put, you'll never have to deal with a shifting, cross-loaded belay carabiner again.