N&C Slimline Slidearm Overhead door closer - Silver cover plate and silver arm. Meets BS 8300 Document M for use on Accessible doors. Suitable for both internal and external doors between 750mm - 1100mm or 20-80kg Max weight. Dual handed for either push or pull operation. 120 minute fire rating. Power size 2-4. Adjustable power by spring, meaning the closer can remain fitted whilst adjustments are made. Back check function to prevent door from being "over-extended" and causing damage to person or property. Closing and latch speed adjustments. 10 year guarantee. Medium duty fire rated door closer.