This is a professional grade adapter designed to convert a single RCA connector to a 3.5mm plug. 3.5mm connections are used in many common audio devices including iPods, MP3 players and smartphones. RCA is commonly used in almost all home theatres. This adapter is small enough to fit into your pocket in case you need to take it with you for temporary arrangements. It is built to last a lifetime and the price is to die for, so why not grab a couple of these to keep around your house?