Features: This item is a magic prop featuring a screw mechanism. It includes internal gimmicks and batteries. The magician demonstrates a bolt and a nut to the audience, then selects one and has a spectator tighten the nut onto the bolt several times. Using hidden mechanisms, the nut appears to unscrew itself and spin off the bolt. The separated pieces can then be handed to the audience for inspection. The items appear to be ordinary bolts and nuts. This trick can be performed without special skills or prior practice. Suitable for both children and adults who enjoy magic and illusions. Specification: Material: Metal Color: As shown in picture Suitable for: Children under 14 years old Battery: 2 x Button Battery (included) Length: Approx. 5 cm / 1.97 inch Packing List: 1 x Bolt 1 x Nut 2 x Battery 1 x Magnet 1 x Glue