Waterproof and designed for marine use Max power handling: 130 Watts Sensitivity: 91dB Frequency: 65Hz20kHz Nominal impedance: 4 Ohms Polypropylene woofer: 6-1/2" Magnet: 11 oz. Mounting hole:. 5" Dia. x 2-1/3" D Titamium Dome Tweeter AS TM B117 Salt spray exposure standard compliant AS TM D4329 UV Exposure standard compliant