The Aerpro ADM140CA Cassette Adaptor allows playback of smartphones and MP3 players through a cassette player. The kit includes with 3.5mm Stereo lead, a 3.5mm stereo lead splitter and dual RCA to stereo lead adaptor. If you still have a cassette player at home or in your vehicle and want to play music from your smartphone or mp3 player this is the product for you.