The CS-4W is a passive 4-inch full-range flush-mount ceiling speaker for indoor 100 V public address systems. It has a rated power handling of 6 W RMS with selectable 3 W and 6 W power taps, a frequency response of 100 to 20,000 Hz, 89 dB sensitivity, and a maximum SPL of 100 dB. The speaker features a rugged metal housing, white finish, 13.5 cm diameter, 8 cm depth, and an 11 cm mounting cut-out. It is intended for speech and background music in permanent installations.