Prospec Electronics SEA-USBMINI Seaworthy Marine MINI-2 Mini Plug for MP3 Players, iPOD and USB Plugs into the back of most JBL and SeaWorthy radios AUX input that allows use of either an iPod,MP3 player or a USB to play through the stereo system Can be used to plug in MP3 players, laptop computers, VHF radios, satellite radios and more Has 72 inch cord Size is of 1 inch - 0.6875 inches diameter