General Features:

Hifonics Zeus ZXX-600.4
Class-A/B 2-Ohm Stable 4-Channel Amplifier
Peak Power Rating:
4 ohms: 75 watts x 4 chan.
2 ohms: 150 watts x 4 chan.
1 ohm: ------------N/A------------
Bridged, 4 ohms: 300 watts x 2 chan.
Total power output: 600 watts
Pulse Width Modulated MOSFET power supply
LED power (green) and protect (red) indicators
4/3/2 channel operation
Preamp RCA outputs to daisy chain multiple amps
3-way protection circuitry (thermal, overload, and speaker short protection)
Heavy duty aluminum alloy heat-sink
Frequency Response: 10 - 45,000 Hz
Signal to Noise Ratio: >90 dB
Variable high-pass filter: 60 - 1,200 Hz 12dB/Octave
Variable low-pass filter: 30 - 250 Hz 12dB/Octave
Variable Bass Boost: 0 to +12 dB bass boost
Fuse Rating: 30 A x 2
4 gauge power and ground wiring is recommended for installation. 
Dimensions: 11.4"W x 10"L x 2.4"H
Also found as: ZXX6004, ZXX-5002, ZXX 600-4, ZXX 600 4, Zeus 600W