2.10m Lengths. 15 x 4mm. Intumescent fire seals expand in the event of a fire and seals off the gap between the door and the frame, preventing the spread of fire and smoke. This combined fire and smoke seal prevents the spread of smoke prior to the fire seal activating. Features low friction brush pile to aid door closing. For maximum effectiveness, they need to be rebated into either the door frame or the door itself. It is very important to fit the correct size seal, please always check fire door manufacturers instructions. As a guide, only use 15mm seals on new door application and 10mm seals for replacement / retrofitting.