Universal 3.5mm Aux Splitter Adapter Extremely lightweight and very compact Splits any 3.5 mm audio jack into two connections Use with Smartphone, PC, stereo, MP3 players, any 3.5mm output jack. Movie or anything else that requires (or is compatible with) headphones. This headphone splitter gives you the option of letting a friend listen to your mp3 player. Video game, movie or anything else that requires (or is compatible with) headphones!