The Nite Ize No 4 Carabiner Slidelock has an innovative slide-to-lock feature that securely locks the gate with a simple push and slide movement, and unlocks when you want it to just as easily. Then, instead of a bulky tubular construction, it has a cross sectioned, rectangular stainless steel body that's durable, low profile, and slim it feeds more easily through smaller openings and rests flat in pockets.