Package: Kicker 11S12L7-2 12" 1500W Dual 2 Ohm Solo Baric L7 Subwoofer + Rockville RXD-M2 750 Watt RMS - CEA Compliant Mono Class D 1 Ohm Car Stereo Amplifier + Rockville RWK4CU 4 AWG Complete Car Am Kit + Rockville RSVK12 Single 12&rdquo; Vented Square Subwoofer Enclosure + Single Enclosure Wire Kit With 14 Gauge Speaker Wire + Screws + Spade Terminals Square vs. Round: More cone area results in greater sound pressure produced by the woofer Rockville RXD-M2 3000 Watt/1500w RMS Mono Class D 1 Ohm Car Stereo Amplifier With Optical Coupler Technology CEA Power Ratings (Rated at less than 1 % distortion): 750 Watts x 1 Channel at 1 ohm &lt;1% THD+N 550 x 1 Channel @ 2 Ohms &lt;1% THD+N, 400 @ 4 Ohms &lt;1% THD+N) (Use these CEA ratings when matching and comparing with other CEA compliant brands such as Kicker, Rockford Fosgate, etc) Rockville RWK4CU 4 Gauge 2 Channel Complete Car Amplifier Installation Kit 100% Pure Copper RCA Cables Rockville RSVK12 Single 12" Vented Square Subwoofer Enclosure