Perkomatic Concealed Hydraulic Door Closer R85PB
The four main springs and the hydraulic unit are contained in an extruded aluminium housing which is let into the butt stile of the door, retained in position by the brass end plate, using brass-plated screws provided. Twin chains terminated by shanks pass through apertures in the anchor plate and through the springs to be riveted to a further plate at the far end of the springs; this plate is bolted to the rod of the hydraulic cylinder. The other ends of the chains are secured to the anchor plate which is let into and screwed to the door frame. Main casing is 168mm long, 60mm high and 22.5mm wide. Anchor plates are 121mm long and 25mm wide.
Please note that this closer is not recommended for use on doors fitted with parliament, projecting or rising butt hinges, due to the chain length being restricted to 1.3/4in. Restricted ventilation or the fitting of door seals can affect the performance as with any other door closer.