HITBEAT 115dB Door KnobHandle Vibration Alarm for Home Hotel Apartment Door Looker Alarm 2 Packs

A Door WatcherHang it on door knob or handle When there is vibration it will make 115DB sounds Static detectingThis function is available only when the door handle is made by metal When someone is going to open the door and has not touched the handle yet The alarm can sense the static electricity carried by human beings and beeps Chime mode to remind you someone has get inout in a friendly wayIf there is a toddler at home use this to provent them from leaving alone Small and portableIdea for front doors apartments hotels bedrooms dorm rooms Take the alarm with you when traveling it is your door watcher your safety guardian and your travelling companySet in 2seconds Placei open go to sleep Three AAA batteries needed they are not included Customers need to purchase separately The three AAA batteries can last approximately 1500 hours in standby mode The alarm beeps for change while low batteries.