12", 1,000-Watt, 4ohm Okur K4-12D4 Subwoofer Heavy gauge stamped steel basket; Injection-molded bowl PP dust cap. High-temp voice Coil, KSV voice coil former. High-excursion butyl rubber surround; Proprietary PVC gasket. Heavy gauge spring terminals. Sealed enclosure vol: 1.15 cu-ft; Ported enclosure min port size: 11-in L x 4-in diameter.