The magnetism can be activated by simply turning a knob

also on the floor and in frames

The countersunk hole ensure that the screw will sit flush when fully screwed on the magnet plate

It is not electromagnetism

on the whiteboard or blackboard

Undersænket pottemagnet, Ø13 mm. - Neodymium ludo mini The magnetism can be activatedCountersunk magnets Diameter: 1. 3 cm. Height: 0. 45 cm. Screw hole: 3 mm. Strength: approx. 3 kg. These countersunk pot magnets (also known as shallow magnets) can be tightened with a countersunk screw (3 mm). A strong neodymium magnet encased in a steel cap (pot). The steel improves the adhesiveness of the magnet as it has direct contact with a thick steel surface. Strength is measured directly on a thick, magnetic steel plate. The strength of the