DOUBLE PROTECTION: The Door Alarm can add a second level of protection lock to the original door lock, and also has more powerful anti-theft performance. SUPER LOUD 120 DB REMINDER: When touched, it will make a loud sound to remind you that there is an intruder, preventing thieves from sneaking into your room and causing damage to your property or ginseng safety. EASY TO USE AND OPERATE: Simple operation, key switch to control the doorbell or alarm, dual mode can be selected, no complicated operation procedure. CAN BE TAKEN WITH YOU: Battery poweRed (without battery), no need for annoying wires, just hang it directly on the knob handle in the door, turn on the switch to activate the protection alarm. TRAVEL PROTECTION: Window Alarm Can be used for travel and hotel accommodation.You can hang this alarm on doors and windows to prevent illegal intrusion. Widely used in home, office, factory.