Serious Power. Seriously Compact. TM400X4ad The Power Marine TM400X4ad 400 Watt 4-channel ultra-compact, amplifier is built on Rockford Fosgate’s proprietary Class-AD technology, allowing the amplifier to produce more power with less current draw from the vehicle's charging system. Featuring Constant Power which results in up to 25% more output power and produces the same output at both 4-Ohm & 2-Ohm impedances. Flexible vehicle integration enabled through low-level and high-level inputs with auto turn-on. The TM400X4ad is marine rated, featuring a two-part marine grade epoxy coated circuit board and UV inhibitor coated chassis, protecting the amplifier from the elements, making it ideal for marine, motorcycle and motorsports vehicles. The TM400X4ad produces more power per square inch than any other model we make! Power Marine 400-Watt Class AD 4-Channel Amplifier Rated Power: 100 Watts x 4 @ 4-Ohm OR 100 Watts x 4 @ 2-Ohm OR 200 Watts x 2 @ 4-Ohm Bridged CLEAN Technology for Quick Set Up Punch EQ Boost Circuit Upgraded RCA Connectors Power Wire Gauge: 8 AWG / Speaker Wire Gauge: 16 AWG Recommended Fuse (not included): 60 A Dimensions: 1.6” x 4.3” x 8.3”