30mm. The ICS GS-705 shear magnet has a holding force of up to 2,700lbs (1,226Kg) with an adjustable time delay of between 1 and 6 seconds. Both the magnet and armature plate have a special zinc finish whilst the housing is black powder coated. It operates on 12/24 V DC and can be installed horizontally or vertically. . Holding force in shear up to 2,700lbs (1,226Kg). Adjustable locking time delay: 1 to 6 seconds. Horizontal or vertical fitting. 12/24V DC operating voltage