Quantum QB4150 Beta Series 4 Channel Stereo Amplifier 4 Channel Stereo Amplifier with class "AB" circuitry, rated at 14.4 volts 4 x 150 watts @ 4 ohms, 2 x 600 w @ (Bridged), 4 x 300 w @ 2 ohms, QSINK heat management system Buffered pre-amp input circuitry, Continuously variable 12dB bass boost @ 45Hz, Continuously variable subsonic filter( 15-55Hz) (Mono Amps) Direct-connect integrated speaker and power wire terminals, Full range RCA line outputs for easy daisy chain configuration, Variable input level control DC-DC PWM power supply, DC short circuit protection, Bass remote capability,Fuse type ATC 1 x 20 amp