Crescendo Encore 4.5k Monoblock Amplifier  Stable down to .5ohm on strong electrical  Up to 18v capable. Custom tooled, Multi-piece High Mass Crescendo Heatsink.  2 stage copper anodized removable top plate.  Gold plated high end hard-wired Tiffany RCA inputs and oversized 2 pair 1/0 Power/Ground Inputs for efficient current transfer.  Overbuilt Power supply with heavy copper traces and Military spec PCB/heavy duty standoffs for extreme vibration resistance. Manufactured using some of the highest quality and most reliable electrical components, with many 3% tolerance components throughout.  Full 4-Stage Intelligent protection Circuitry 1 Year/1ohm comprehensive warranty with 2 year/.5ohm optional extended warranty available.  Rated Power Output(RMS)  Clean RMS power on 13.8v standard electrical system: Ohm Load Encore 4.5k 1ohm 4500 2ohm 2500 4ohm 1250   Dimensions: E4.5K: 25.6"L x 2.4"H x 9.45"W (at widest point)