DS18 HYDRO BTRC-R Marine And Powersports Round Waterproof Universal Bluetooth Streaming Digital Media Receiver with Functions Control (Works with android and iPhone) There are many applications that do not have much room for large bulky head units or sometimes come with no source output at all. Now you can add BT connectivity for any audio system with our easy to use BT remote control. This BT remote mounts easily in every application and takes up almost no space