The 3.5mm to cassette adaptor can be used with entertainment systems that have audio cassette tape decks connect the 3.5mm stereo jack to the output source such as an mp 3 player. Specification Cassette Adaptor Play any portable CD or MP3 player through any audio cassette player Supports: MP3/MD/CD/VCD/DVD/PDA/ Game Boy/iPod Frequency: 30-20 000 Hz Plug: OD.3.5 DT.P/NI Cable Length: 120cm Colour: Black