No batteries or electrical required, easy to use Unique Magnetizer can also be used to demagnetize tools With high safety performance Stable and reliable for long time use Practical,bring you much convenience For screwdriver increasing the magnetic or eliminate magnetic. Increasing the magnetic is easy to pick up small screws. Size: 40x28x20mm Material: Plastic Color: yellow How to use: Add magnetic :Slide the screwdriver tip repeatedly in the "+". Degauss: Slide the screwdriver tip repeatedly in the"-". Package include: 4 x Demagnetizer Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.