The IA-303 adaptor cables allow you to connect one guitar and one portable music player into one 1/4" phone jack input on your instrument amplifier. This adapter will work with passive or active pickups found in most guitars as well as basses. Simply plug in your instrument and music player using the headphone jack and balance the volume using the normal volume controls on your guitar or bass as well as on the music player. The special (patent pending) design will combine the signals without the