Feature: 1. Pure copper electromagnetic coil with discontinuity and no electromagnetic interference. 2. Strong tapping, stable operation and long service life. 3. Hard metal shell, not easy to deform, the sound reaches 95db, and it is farther and safer. 4. The surface is coated with electroplating technology to make the material more anti-corrosive and less prone to rust and corrosion. 5. Portable wired power supply, easy to install, can be installed on the wall, ceiling and other installation methods. Specification: Features: Pure copper electromagnetic coil with discontinuity and no electromagnetic interference. Strong tapping, stable operation and long service life. Hard metal shell, not easy to deform, the sound reaches 95db, and it is farther and safer. The surface is coated with electroplating technology to make the material more anti-corrosive and less prone to rust and corrosion. Portable wired power supply, easy to install, can be installed on the wall, ceiling and other installation methods. Choose 12V / 24V / 220V according to the voltage you use. The maximum range is 600-800 square meters. Specifications: Condition: Brand New Color: Red Material: Carbon Steel + Bottom Plastic Size: 6 inches (150mm) Power Mode: External Optional Voltage: AC220V/DC 24V/DC12V Alarm Volume: 95db Surface Treatment: Electroplating Package List: 1 * Internal Strike Bell Note: 1. It is used in an environment where there is no flammable or corrosive gas or conductive dust in the surrounding air without significant shaking and shock vibration. 2. It can work normally when the rated voltage is ±10%, and it can work continuously for no more than 10 minutes.