Magnetizer / demagnetizer C-MART Magnetic / demagnetizer is useful to provide a magnetic power or eliminate the magnetic power on the equipment you tools such as a screwdriver or other tool tooling. The use simply by swiping equipment tools Magnetic iron into the hole so that you have a magnetic power. While demagnetizer is used to remove the magnetic power on the equipment / tool that already has a magnet. The size of the hole: 27 x 15 mm