1. This alarm is operated by a 9V battery.
2. Open the battery door on the back side of the alarm unit. And place a 9V battery in the battery compartment. Make sure the battery is installed correcly before use. See fig. 1.
3. After installing 9V battery, place the doorstop alarm behind a closed door to secure the room.
4. if the secured door is opened, the edge of the door will press down on the wedge plate of doorstop alarm and set off the alarm, whichi will sound at 120dB siren continuously.
5. The sensitivity of the vibration sensor can be adjusted from low to high as indicated in order to meet your needs. See fig.2.
6. When the siren starts to sound weak, it is time to change the 9V battery as described in step 2 .
7. Turn the power switch off when the doorstop alarm is not in use. The alarm unit can be used as a doorstop to prevent the doorknob from hittng the wall if the binged door is opened too roughly.