CS-Series 4x10-inch Coaxial Speakers give you the quality you want, with the factory fit you need. The CS-Series design features near-zero tweeter protrusion, so your speakers fit perfectly behind factory grilles. This simple, drop-in solution delivers acclaimed KICKER performance with a stamped-steel framework, rigid polypropylene cone and EVC (Extended Voice Coil) technology. You get superb clarity, durability and volume – now and way down the road! Fits nearly every car made that requires 4x10s, especially older GM models Zero-protrusion tweeters to fit nearly any factory depth Woofer EVC (Extended Voice Coil) tech assists with precise linear excursion UV-treated poly-foam surround resists heat or direct sunlight Large woofer magnet in a heavy-duty motor for ultra-clean bass PEI-tweeter construction provides superb clarity Neodymium tweeter magnets allow for increased volume in high frequencies Specifications Speaker Design: 2 - way Woofer Size [ in, mm ]: 4x10 [100x250] Tweeter Size [ in, mm ]: 1/2 [13] DC Resistance [ ohm ]: 3.3 Peak Power [ watts, per ANSI/CTA-2031-A ]: 225 Recommended Amplifier Power [ watts RMS ]: 75 Sensitivity - SPLo [ dB @ 1W, 1m ]: 88 Effective Frequency Range [ Hz ]: 45-20k Mounting Hole Diameter [ in, mm ]: 3-7/8 x 9-5/8, 90 x 238 Top Mount Depth [ in, mm ]: 2-3/8, 80 Bottom Mount Depth [ in, mm ]: 2, 50 Tweeter Protrusion [ in, mm ]: 0 Grilles: No Tweeter Magnet Material: Neodymium Tweeter Dome Material: PEI Tweeter Design: Balanced dome Woofer Cone Material: Polypropylene Woofer Surround Material: Polyester foam