This mushroom knob is an ultimate child safety product. Hidden inside cupboards and drawers, the locks can only be released with the use of the powerful magnetic key. Automatically locks when the door or drawer closes. To release, simply place the Magnetic Key on the outside of the cupboard or drawer and turn. Convenient disengaging clip means the door can remain unlocked when necessary. It suitable for cabinets thickness from 12mm (0.5") to 28mm (1.1").