YM0428Y The bolt is equipped with a hidden gear and battery which can spin and automatically detach the nut from screw First screw the bolt and nut together The magic moment comes when the nut on the bolt begin to automatically spin and finally completely detach from the bolt Amaze your audience and enjoy the applause Dimensions: 5 x 1 x 1 cm   Package Details Weight: 34.24 g Size: 13.00*9.00*1.00 cm Package Includes * Bolt & Nut Automatically Detaching Magic Kit