The magician shows a large, heavy, brass nut and bolt and a padlock to the audience. He asks for the loan of a finger ring. He places the ring onto the bolt and fixes the nut in place. The only possible way to remove the ring from the bolt is to unscrew the nut, this is rendered impossible by securing the padlock through the hole in the end of the bolt. Therefore, the nut cannot be removed without first unlocking and removing the lock. The bolt is placed on the table and covered with a handkerchief. The magician shows his hands empty and reaches under the handkerchief for a second. He then whips away the handkerchief and the borrowed ring is free from the bolt. The bolt is still secured with the lock and nut! 

In another presentation,The magician borrows a finger ring and causes it to vanish. The missing ring is discovered securely locked on to the locked bolt! Only one bolt is used, No switches, No magnets. EVERYTHING CAN BE IMMEDIATELY EXAMINED!​​​​​​​