The Perkomatic automatic door closer (R85) incorporates a combined hydraulic mechanism and spring assembly and offers a controlled rate of closure and good fire resistance making it suitable for use on latched ½ hour and 1 hour fire doors. It incorporates a latching action to overcome the resistance of the latch even when the door has been opened by only a small amount. The latching action is controlled by adjusting the point at which this action takes effect.

Main casing is 168mm long, 60mm high and 22.5mm wide. Anchor plates are 121mm long and 25mm wide.