Standard Horizon MLS410PAW External Speaker With 10W Amplifier, 5″, WhiteThe MLS 410PA is a 10W amplified speaker designed to work with the current VLH 3000A and past models GX2000, and GX2200 (not compatible with any current model VHF's from Standard Horizon). The MLS 410PA is designed to be connected to a 12V source to power the 10W amplifier and provide much louder audio than you would get from a separate passive speaker. The MLS 410PA also includes a volume control knob on the front to manually adjust audio ouput right