Play Your Digital Audio Through Vintage Equipment : Chargeworx’ Cassette Adapter lets you use your vehicle’s tape deck to stream music and audio from a smartphone, laptop, cd player, mp3 player to your car’s speakers system. Also connects most modern aux-jack compatible devices to a boombox or component cassette deck. | 31-Inch Universal 3.5mm Plug: Connects to most standard headphone jacks or aux line out ports with plenty of slack to spare. The cord is sturdy and slender enough to fit through the closed cassette tray door on most outboard decks and components. | Front and Side Loading Options: The CX9991 Adapter looks and works just like your traditional compact cassette tape. It’s plug and play, which means no wiring is necessary, you simply insert it into your front or side loading cassette tape player, deck, or boombox, connect the other end to a device with aux-in and you’re all set to send mp3’s and other digital audio files through your older media. | Works with CD and MP3 Players: There’s vintage, and then there’s Vintage. Let’s say you want to hear audio from that trusty, portable compact disc player or MP3 stick through your car speakers; it’s the same set up. Connect these devices (that have aux out ports) to the vehicle’s cassette deck, and turn it up!