Tick Tock by Sean Goodman
Item Number: TA9275
Two watches are handed to two spectators to examine. Each spectator unclicks the crown of their watch and turns it - the hands spin freely and fairly. The watches are now held face down and each spectator turns the crown uintil they feel the urge to stop - the crown is now clicked in place, the time is set.
The times on both watches match. Perfect!