Keeper plates are normally used together with our electromagnetic door holders as counterpart to the magnet. The keeper plate is mounted on the door and equalizes small irregularities so the door is always fastened by the magnet.
The keeper plate has to be selected according to the size of the electromagnetic door holder. The diameter of the plate should always exceed the solenoid. The keeper plate with adjustable angle is included in most of our fire door retainers.
The holding surface is ground and protected against corrosion by means of zinc plating.