The Rockville RWK42 4 AWG (American Wire Gauge) amp kit has the following diferences over other amp kits on the market at this price point. Package Includes: (1) Rockville dB55 4000 Watt/980 Watt Dyno-Certified RMS 5 Channel Amplifier Car Stereo Amp, Loud!, Loud!!. (1) Rockville RWK42 4 Gauge 4 Chan Car Amp Wiring Installation Wire Kit (2) RCA's. Includes: Amplifier. Bass Remote. Birth sheet with tested power. Owner’s manual. Mounting Screws. Warranty. Rockville dB55 4000 Watt/980 Watt Dyno-Certified RMS 5 Channel Amplifier Car Stereo Amp, Loud! Dyno Certified RMS Power Ratings: (Certified Dyno Test / Less than 1 % THD) (Use these ratings when comparing with top brands such as Kicker, Rockford Fosgate, etc) - 2 Ohm: 120 Watts x 4 + 500 Watts x 1 <1% THD+N - 4 Ohm: 80 Watts x 4 + 300 Watts x 1 <1% THD+N. Peak: (Use these ratings when comparing with the top budget brands such as Boss, Power Acoustik, etc) - 2 Ohm 480 Watts x 4 + 2000 Watts x 1 - 4 Ohm: 320 Watts x 4 + 1200 Watts x 1. High-Speed MOSFET Power Supply Rugged switching MOSFETs for Class D in CH5. Under Voltage Protection at 10V. Over Voltage Protection at 16V. Optical Coupler Class “AB” +“D” Technology. Studio-Grade Bipolar Output Stage Transistors. Fully Adjustable 12dB / Octave Crossover with Differential Circuitry. Low Pass Filter: (CH1-CH4)40Hz –4KHz /(CH5)50Hz –250Hz. High Pass Filter: 15Hz – 4KHz. Subsonic Filter: 15Hz - 55Hz. Full IC-Controlled Protection Circuitry. Remote Dashboard Subwoofer Control Fully Adjustable 12dB Bass Equalizer. Mute and Delay Soft Start System. 8 Volt Preamp Circuitry. Status Mode LED Indicator. Minimum THD at Rated Power: < 0.05%. S / N Ratio: >90dB. Frequency Response: 15-35KHz. Damping Factor: >100@ 100Hz. 40 Amp x3. Dimensions: (W x H x L) 9" x 2.4" x 18.6". Rockville RWK42 4 Gauge 4 Channel Car Amplifier Wiring Installation Kit. (2) 17 High Grade Twisted Pair of 100% Copper RCA Cable. 17 4 Gauge Translucent Blue SuperFlex Power Cables 17 18 Gauge Blue Remote Cable. 17 16 Gauge Clear Speaker Wire. 3 4 Gauge Clear SuperFlex Ground Wire. Gold Plated AGU Heat Resistant Fuse Holder. 80 Amp AGU Gold Plated Fuse. 7 Split Tube Loom. Accessories Included: Wire Ties, Ring Terminals, Butt Connectors, Spades, and Grommets. Soft abrasion proof insulating jacket allows for 100% improved flexibility. PVC outer jacket can with-stand an extreme temperature range of -40 to 220 degrees F