No sound system is complete without the perfect subwoofer for complementary base. The SWR-M100's high excursion abilities mean deep, high-output bass for great on-water performance. Infinite baffle design for widest application. Custom, high strength polypropylene frame. Thermal management system. Hidden screw mounting and grille design. Waterproof rubber mounting gasket included. 900 watts peak power handling. 4 ohm impedance. Mounting depth: 5-11/16". Mounting diameter: 9-1/32".