-Rugged all-steel surface-mounted enclosure; off-white finishBuilt-in 1W amplifierFull range 8" cone speaker for excellent intelligibilityBuilt-in volume control with detachable knobAvailable as flat-fronted (AMBSQ1) or with 12.5° angled front (AMBSL1)Self-contained 1-watt amplifierInterfaces with standard 600-ohm telephone lineKnockouts for Wiremold®Mounting hardware included (toggle bolts, wood, screws, pluggable screw terminals, volume knob)