Marine Stereo System Receiver. Tuner Section FM Stereo Frequency Area US, Europe. Bluetooth: long distance music Streaming. RMS Power Output: 4 x 45W. Power supply: DC 12V. Meets ASTM B117 salt/fog standard. Input Types: Bluetooth, USB, AUX. Outputs: 1 pair RCA Pre-Amp Out. Waterproof 4 INCH Speakers. Mounting Hole Diameter: 115mm(4.52). Mounting Depth: 35mm/(1.37). Frequency Response: 120Hz – 20kHz. Grill material: UV Plastic. Magnet Material: Ferrite, 4oz. Magnet Protection: Plastic Water Guard. Application:Boat, yacht, SPA, swimming pool, ATV, UTV. Maine Waterproof Rubber Antenna. Marine Rubber Radio Antenna. Waterproof and resists corrosion. Perfect for boats and campers. 13.3inch Long Mast. All items will be tested in advance before sending out. It is easy for us to contact the logistics provider to inquire about the package. Marine series of head units and remotes are fully tested against UV radiation degradation as well as tested to IP66 water intrusion standards. We also fully test the stereo units for every changing environmental conditions that you may experience on the boat or out in the dunes such as temperature extremes, as well as vibration testing to make sure they can take a bump and keep performing as a high standard product. If you are dissatisfied for any reason, please donot be quick to leave negative/neutral feedback. Our working time:Monday to Friday.