new and high quality Requires no special wire Just hang on the inside door knob, open the switch, the piercing alarm scare off any unwanted intruders, leaving you and your home well protected 120 db supper loud alarm ringing Alarm For Door Knob Enhanced Security for Your Home: The for Touch Door Knob Entry Alarm Alert Security Anti Theft system is an essential addition to any household looking to safeguard against intruders. Designed for simplicity, this alarm system requires no special wiring, making it a breeze to install. Simply hang it on the inside of your door knob, switch it on, and the piercing 120 dB alarm deter any unwanted visitors, ensuring your peace of mind. Robust and Reliable Performance: Crafted from ABS plastic, this alarm is built to withstand the rigors of daily use. Its compact size means it 't get in the way of your door's operation, while its design ensures it 't add unnecessary strain to your door knob. The alarm's 120 dB volume is more than enough to alert you and your neighbors of any suspicious activity, providing a sense of security that's hard to match. Versatile and User-Friendly: This door knob alarm system is not only effective but also versatile. It's suitable for a wide range of door knobs, ensuring compatibility with most standard door knob sizes. The alarm's sleek design blends seamlessly with your door knob's aesthetics, making it an unobtrusive addition to your home's security setup. It's a perfect solution for homeowners, renters, and anyone looking to safeguard their property without the need for complex installation or monthly fees. Power Source: 9V Battery (not included) Alarm Volume: 120 dB Dimensions: 99mm x 55mm x 27mm Weight: for easy installation Design: Sleek and unobtrusive, blends with door knob aesthetics Color: Black Material: plastic Package Contents: 1 * Alarm (without 9V Battery) Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.