"TOGS" stands for Triple leg, Oblong master link & GS is a self-closing safety hook with a built-in safety handle.
A Safer Rigging Hook
These Grade 100 chain slings feature an oblong master link on one end and three self-closing Grip Safe hooks on the other end. Grip Safe hooks allow the user to grab hold of the hook and manipulate the safety trigger (which allows the self-closing latch to open and close) without putting his or her hand inside the load-bearing area of the hook. These hooks also offer a wide throat opening and a rugged alloy latch that holds up better than the latch on a standard sling hook.