Fail-safe operation, tri-volt coils, and an adjustable armature plate allows for easy and flexible installation. The faceplates are made of cast iron and door holders come in 2 mounting styles: surface-mount (DH-151SQ) and flush-mount (DH-171SQ).

The adjustable armature plate reduces the installation time, adjusts to door alignment changes, and has a low profile design. Doors are held securely with a holding force of 35-lbs (15kg) and when released there is no residual magnetism. The door holders have built-in voltage spike suppressors and support 3 voltages: 12/24 VAC/VDC, and 120VAC.

The door holders can be used with any Seco-Larm door closers. The extension bars are available separately in 9 sizes varying from ½ an inch up to 7 inches.