Description:Wide ApplicationThese door entry alarms are suitable for various kinds of doors and windows with handles, applied in families, rental rooms, dormitories, hotels, shops, warehouses and other anti-theft places, also a effective helper for travel to protect the safety of you and your family Dual-mode alarmswitch and alarm mode are in one built-in key, push up is doorbell, push down is alarm sound; When the door handle detection alarm is not used, the switch key can be restored; In addition, the alarm sound is up to 120dB, no omissions, no false alarms Working PrincipleHang up the home security alarm triggered, and after the red light flashes for about 30 seconds and stops, the door alarm officially enters the alarm state; When someone touches the door handle or opens the door or window and generates vibration, the alarm will ring immediately to remind you Easy to Use Just insert 3 batteries (not included) into the alarm for the door handle, turn on the side switch, and hang the alarm inside the door handle to enjoy a safe living place Service GuaranteeWe are very professional sellers. If you have any questions during use, please feel free to email us. We will do our best to help you solve the problem. Please feel free to buy, thank you for coming