Monitored. This high strength double magnet from Adams Rite's Armlock 281 range boasts a magnetic holding force of at least 510kg and it is suitable for use on outward opening aluminium, timber or steel doors. These magnets are fail unlocked and they are available as either monitored or non-monitored.. Facilitates remote access and exit control of any aluminium, timber or steel door. Features clean aesthetics. Maintains a magnetic holding force of at least 510kg (1120 lbs). Durability and low maintenance