The KTP-445U Universal Power Pack amplifies the head unit power output, resulting in up to a 150 percent power increase over the original power from the head unit’s built-in amplifier. Add higher output and more dynamic response with this easy-to-install head unit power upgrade. Features For aftermarket and factory installed systems Compact size 4-channel Amplifier 45 Watts x 4 @ 4Ω/2Ω 90 Watts x 2 @ 4Ω Bridged Fuse: 15A Specifications Power Output Per Channel, Ref: 14.4V, 4ohms, @ < 1% THD+N: 45W RMS x 4 Per Channel, Ref: 14.4V, 2ohms, @ < 1% THD+N: 45W RMS x 4 S/N Ratio IHF A-wtd + AES-17, Ref: 1 W into 4 ohms: 82dB IHF A-wtd + AES-17, Ref: Rated Power into 4 ohms: 98dB Frequency Response +0 / -3 dB, Ref: 1 W into 4 ohms 15Hz – 45kHz Input Impedance > 10k ohms Input Sensitivity Ref: Rated Power into 4 ohms, RCA Inputs: 0,2 – 4,0 V Ref: Rated Power into 4 ohms, Speaker Level Inputs: 0,5 – 10,0 V Crossover Ch 1 / 2: Selectable HPF (-12 dB/oct.), defeatable: Off/60/80/120Hz Ch 3 / 4: Selectable HPF (-12 dB/oct.), defeatable: Off/60/80/120Hz Dimensions Width: 189.0mm (7-7/16”) Height: 38.2mm (1-1/2”) Depth: 64.5mm (2-1/2”) Weight: 0.8kg (1,5lbs)