RCF L12L750 Vehicle Speaker 4-inch, fiberglass former, edge wound aluminum voice coil700W continuous program power handling101 dB Sensitivity 60 Hz - 2 kHz Frequency range Shaped Shallow Triple-roll damped surround Inverted dust cap The aluminum voice coil offer a properly aligned Q factor and a very high sensitivity. A specially designed Shallow Triple-roll surround guarantee a very low midrange distortion.