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..
the alarm sound will starte for 30 seconds.
Mr. Mike Zhen
Hefei Long River Electrical Co.,Ltd.
Tel:+86 13956994028, longriver.en.made-in-china.com