HiFi sound quality incorporating "Dynamic Loudness" system for perfect bass and treble compensation at low volumes of music. 20 W RMS 40 W musical program, of maximum audio output power, for connection from 1 to 8 speakers or box loudspeakers of low impedance. Electret-unidirectional microphone for enhanced voice clarity. Key switch to turn On/Off status. Extra PIN output for activation and amplification of supplementary sound through EGi power stages. Push button for call messages with priority over any music. Led indicators for Music signal bluetooth, AUX, calls and On/Off status. Built-in external power supply 115/230 Vac to 15 Vdc via female Jack coaxial connector.