Third Hand Floating Card

Dream Lock

Now this is indeed a Dream Lock. This lock enables effects like a dream...

A borrowed ring is locked on a 4 digit combination brass lock and the dials are mixed.
A spectator can test that the lock cannot be opened. The spectator thinks of any 4 digit number dials them on the lock.
And only that secret number opens the lock!
No force of any pre-conditioned numbers.

Whatever numbers the spectators have chosen, they put the numbers and open the lock with their own hands!

Important points:
Mechanical, nothing will break
Nothing added or taken away
No electronics parts, no remote control
No magnets, no PK rings
No threads, no wires
No buttons, no switches
No gravity switch, no directional limit
No timers
Spectators set the chosen numbers on the lock.
They open it themselves!

Difficulty: