600 series commercial-grade constant-voltage & constant-impedance dual-function ceiling speakers, patented voice enhancement technology, patented bass enhancement technology, front inverted hole, with metal acoustic back box, suitable for all kinds of commercial & office & meeting places.
600 series commercial-grade constant pressure & constant resistance dual-function hanging speakers, patented voice enhancement technology, patented bass enhancement technology, front inverted hole, wide sound field coverage, suitable for various retail stores, large supermarkets, shopping centers, clubs, etc. An empty high environment.