door stop alarm put the alarm at the botton of the door in room. the metal plate will detect the door moving and alarm about 30 seconds 3 pcs AAA battery 100db loudness DOOR STOP ALARM YL-161 4.5v 3 pcs AAA battery 100 db (30 cm) Open the battery cap and put in the batteries. put the alarm to the ground of a door back. Switch on the alarm. When the door is opened and touch the metal plate of the alarm.. Then the alarm will started for 30 seconds. Open the battery cap and put in the batteries. put the alarm to the ground of a door back. Switch on the alarm. When the door is opened and touch the metal plate of the alarm.. Then the alarm will started for 30 seconds.
