8" Cone speaker. Self-contained 1-watt amplifier. Interfaces with standard 600-ohm telephone line. Available on an off-white semi-gloss enameled ceiling grille (ASWG1, ASWG1DK), or bright white finish ( ASUG1, ASUG1DK). Ceiling assembly with fixed front-mounted volume control knob (ASUG1, ASWG1).