Knauf FR (Fire Rated) Putty Pads are an easy-to-apply fire and sound rated sealant supplied as a non-setting putty. The pad is hand workable, re-useable and re-serviceable due to its non-setting properties. Field of Application: Internal Fixing:Insert the pad into the socket back box so that the pad completely covers the back and sides. Make a slit to allow the wires to pass through the pad. Rear Fixing:Place the pad over the socket back box so that the pad completely covers the back and overlaps onto the dry lining partition.