Features: -It uses a 110dB high decibel alarm, which can play an effective warning role. -Using high-sensitivity sensor, the alarm will be triggered immediately when the door or window is opened 1 cm. -Using double-sided tapes for installation, no drilling, no tools required, easy to use. -Powered by 2 AAA batteries (not included), energy-saving and low-consumption, the lights of the remote control and the host will flash to remind when the power is low. -Using reed switches and industrial-grade chips to ensure low false alarms. -Suitable for rental houses, dormitories, hotels, warehouses, shopping malls, shops, villas, etc. .