1Pure copper electromagnetic coil with discontinuity and no electromagnetic interference. 2Strong tapping, stable performance and long service life. 3Sprayed iron cover, not easy to deform, the sound is louder and farther. 4The surface is electroplated, anticorrosive and antirust. 5Easy to install, can be used for hanging arms, ceiling mounting. 6Applicable to industrial and mining, government groups, public places and equipment supporting 50HZ, also suitable for doorbells, alarms, etc.
