Monitored. This double magnet from Adams Rite's Armlock 261 range features a magnetic holding force of at least 250kg 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.. To facilitate remote access and exit control of any aluminium, timber or steel door. Combines a compact case size and clean aesthetics. Maintains a magnetic holding force of at least 250kg (550lbs). To suit outward opening doors