Bogen Communications MB8TSL 8-Inch. Metal Box Speaker is a steel surface mounted speaker enclosure. The MB8TSL features an 8-in. cone speaker and a 4W 70V25V multi-tap transformer. Includes mounting hardware. Features: All steel enclosure surface mounted. 8 inch full range. cone speaker for excellent intelligibility. Compatible with 25V or 70V amplifier systems. Multiple outlets at 4 2 1 12 14 18 watts. Maximum output power of 4 watts. Mounting hardware, such as toggle bolts, wood screws, and wire crimps. VR models feature recessed volume control in the center of the front speaker grille