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. The maximum range is 600-800 square meters. Specifications:Condition: Brand NewColor: RedMaterial: Carbon Steel + Bottom PlasticSize: 6 inches (150mm)Power Mode: ExternalAlarm Volume: 95dbSurface Treatment: ElectroplatingPackage List:1 * Internal Strike BellNote: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..