CERWIN VEGA V3152 15-Inch Dual 2 -Ohm V3 Series Subwoofer High strength composite polypropylene cone Butyl rubber surround O2 Cast heavy duty aluminum basket XFV Cross-flow window venting allows for massive heat dissipation from the voice coil Pushpin terminals Linear rolled spider with over-under weave design 2-1/2" High power dual voice coil with rolled aluminum former Resonance Frequency (Fs): 29 Hz Top-mount depth: 7-1/4" Sensitivity: 87 dB