Wide Application These door entry alarms are suitable for various types of doors and windows with handles, used in families, rental rooms, dormitories, hotels, stores, warehouses and other antitheft places, also an effective helper for travel to protect the safety of you and your familyDualmode alarm switch and alarm mode are in a builtin key, press up is doorbell, press down is alarm sound. When the door handle detection alarm is not used, the switch key can be reset. In addition, the alarm sound is up to 120dB, no omissions, no false alarmsWorking principleHang up the home alarm that is 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 vibrations, the alarm will ring immediately to remind youEasy to use Just insert 3 batteries not included into the door handle alarm, turn on the side button and hang the alarm inside the door handle to enjoy a safe homeService GuaranteeWe are very professional sellers. If you have any questions during use, please email us. We will do our best to help you solve the problem. Please dont hesitate to buy, thank you for coming