Live & USD. A solid brass, genuine padlock. Five keys are given out for the spectators to try in the lock, none of them open it! A sixth key is introduced and shown to be the ONLY ONE that will open the lock. A borrowed ring is then locked onto the padlock and all six keys are then mixed together... Five of the keys are removed leaving only one for the owner of the ring... Surprise! Yes, it is the one that opens the lock!!! The ring is removed.
It can be used to lock a borrowed ring onto the hasp, a box, bag etc, the performer or spectator can always choose the correct key.

Many different routines are possible, the only limit is your imagination