These are two PowerBass S-104D high-performance 1100 watt 10 inch car audio subwoofers. Featuring dual 4-ohm, 2" inch voice-coils these S-Series subwoofers can pound out an amazing 1100 watts total power (550 watts RMS). Also featured, are large pro-lock terminals. These terminals enable you to wire these powerful subs with large gauge cables into a 4 or 2 ohm load. The 4-layer wool/paper cone, high-roll treated foam surround, oversized 116 ounce motor assembly and stamped steel basket; allow these powerful subwoofers to produce more excursion without bottoming out and lower distortion. This equals deeper bass and higher SPL levels. These subwoofers are well-suited for small sealed or ported enclosures or other bass applications. You can use a mono amp, 2-channel or even a 4-channel amplifier to run these subs.