Packing a powerful punch in a compact size, this 2 in 1 Magic Door Alarm emits a piercing 120 dB sound to scare off potential intruders. this is a dual purpose alarm: It acts as a burglar alarm and a personal alarm. Hang it on any doorknob (non metallic doors) and it instantly and automatically sounds when an intruder touches the door knob. the alarm will also work if an intruder is wearing gloves as this alarm will detect the body's electricity.