1. Hook security stop lock 2. color: white, black, red... 3. diameter: 4, 6, 8, ... , 5mm 4.the way to unlock: detacher Hook security stop lock Security Hook, display hooks,pegboard hooks,supermarket hooks,gift shop ... : Red, blue, white, black, ect Other details information1. The stop lock is used for display sales of big malls, chain shops ...