Anti-interference: Pure copper electromagnetic coils have the advantages of discontinuity, no electromagnetic interference, strong tapping force, stable and long service life. Loud sound: Hard metal shell, not easy to deform, the sound reaches 100db, the maximum range is 600-800 square meters, more secure. Simple installation: Portable wired power supply, easy to install, can be installed on the wall, ceiling and other installation methods. Anti-rust and anti-corrosion: The is plated with electroplating technology, which makes the material more resistant to rust and corrosion. The excellent technology allows the bell to pass rigorous tests under extreme conditions. Widely used: 3 kinds of voltage selection, select 12V / 24V / 220V according to the voltage you use. Can be widely used in fire fighting, emergency evacuation, factory alarm, school bell, etc., Weight: 0.440924524 pounds, Manufacturer: Dioche