The NV-7565 is a fireproof ceiling speaker built-in 70v/100vtransformer. The 70v/100v transformer technique reduces line losses on longerdistance and allows easy parallel connection of multiple loudspeakers.The built-in 5"speaker driver is designed of wide frequencyresponse 130-18KHz, the multiple power taps 0.38W, 0.75W, 1.5W, 3W & 6W are helpful for different applications varies from room size and ambient noisesurroundings.The metal grille, metal baffle and fire dome metal back can plusceramic connector, thermal fuse and fire-resistant cable, all of the abovefeatures make it is fireproof. Its spring clamp type makes the easy and secureinstallation.This fireproof ceiling speaker is specially designed for fire alarm andvoice evacuation system, which is designed and manufactured according toEN54-24 standard. It is ideal choice for industrial and commercial applications inhotel, school, office and factory where background music and paging is needed