Size: 18-InchThis Sound 8 Ohm 18 inch driver has a max wattage of 340 watts and is designed and engineered right here in the USA. This subwoofer Features a 50oz magnet with Bumper plate, vented pole piece, accordion edge surround and polymer laminated cone. This subwoofer is a high end, Pro audio transducer optimized for all musical instrument, DJ, car audio and professional applications.