The stainless steel collar is locked with an Allen screw and can be opened with the included Allen key. Keep your sub secured on a leash and under your control with this thick iron collar. The durable and heavy steel fits snugly around your sub's neck and holds them firmly. The collar features an O-ring for attaching chains, straps, or other restraints. This means you can securely lock your sub with the toys of your choice. You can even attach a leash to the collar and lead your sub, who must obey all your commands.