Awesome and unique white rollerball switch consists of a ball, a magnetic ring, and a reed switch, all inside of a 2" long x 0.73" diameter housing. The switch is mounted on a table and the valuable object to be protected is placed on top. If the object is removed, the switch contacts open. Used also on window frames, doors, sliding objects, etc. Features, contacts that are closed when ball is pushed into switch, and contacts open when ball pushes outward again. Brand new, type DC-3711 by Aleph. Retails for $2.75 for one.
Sold in a package of 5.