Alarm/blockade for doors, proves effective in residential buildings, offices, shops, warehouses, etc. The device should be placed under the door; when an attempt is made to open it, it will be blocked on the wedge principle and a very loud alarm (125 dB) will be triggered. The alarm will automatically turn off after 1 minute. It can also be mechanically stopped using a switch. Power supply - 1 x 9V battery (not included).