Soundlab A121B 1.2m audio cable with minijack 3.5mm small stereo jack plug on one end and 2 RCA phono plugs on the other.
This type of cable is primarily used for splitting a stereo signal in order to plug e.g. an iPod into your surround sound system.
It can also be used the other way round in order to join a stereo signal and capture on your computer e.g. plugging an old cassette player into your sound card's line-in port.