Designed to withstand the harsh marine environment and comply with International ASTM Standards for UV Stability (ASTM-D4329) and Salt/Fog Resistance (ASTM-B117). (IP65) waterproof & dust standards. Efficiency (1W/1M): 87db Frequency response: 90Hz-22kHz Impedance: 4 Ohms Magnet type: Shielded Max power (Watts): 120 Mounting depth: 60mm (2.36") Tweeter type: titanium dome