No batteries or electricity required. Easy to use. Just insert the object into the corresponding cavity for several times for magnetizing or demagetizing. To magnetize or demagetize screw drivers, tweezers, tool bits, screws and other steel objects. Useful for demagnetizing tools before use on magnetically sensitive surfaces for electronic work. Perfect tool for carpenter, mechanic, DIY lover and others in shed or workshop. Helps to give a magnetic property to make screws easily to pick up., Manufacturer: Zerodis