USB Interface & 1/8 Auxiliary Input Jack. Waterproof design;USB port allows for connection of external storage device;1/8 audio jack allows input of any MP3 player or external audio device;Audio connector (RCA) .10 ft. Cable Length.For use with any stereo with USB capability and/or auxiliary audio inputs;ASTM B117 Salt Spray Exposure Standard Compliant. ASTM D4329 UV Exposure Standard Compliant