Dayton Audio UM10-22 10" Ultimax DVC Subwoofer 2 ohms Per Coil Dual 2 ohm, 2-layer copper voice coils Large vented pole piece and under-spider venting 500 watts RMS power handling Black anodized aluminum former and black pole improves heat dissipation Thick, one-piece Nomex honeycomb covered cone with woven heavy-duty glass-fiber