Sold as a pair, the white JBL Control 24CT MicroPlus is a passive 4.5" low-profile ceiling speaker with a 25W multi-tap transformer designed for voice amplification and background music reproduction in a variety of venues ranging from retail stores to restaurants. When driven by a 70V/100V power amplifier (available separately), the 4.5" injection-molded graphite woofer and 0.5" polycarbonate tweeter yield a frequency range of 80 Hz to 25 kHz. A built-in crossover network ensures proper distribution of frequencies to the speaker components.