Concealed chain spring door closer, recommended for internal doors, they are fitted into the door edge, with the chain plate attached to the frame. When the door is opened, the spring recoils and forces the door to shut. Chain tension can be adjusted allowing a good degree of flexibility in setting the door closing rate. Square and Radius end version available. Fire tested. Fire certificate BS476:PART 22:1987. Comes with a 10 year mechanical guarantee. Faceplate size 45mm x 25mm, suitable for doors upto 45kg.