The KA-333 connects from the earphone or headphone jack output of a voice recorder to the microphone input jack of another recording device. With the KA-333, you can transfer recordings from your voice recorder to another voice recorder. You can also use the KA-333 to transfer recordings from a voice recorder to a PC or home stereo (check your PC or home stereo for jack compatibility). The KA-333 has a 3.5mm Stereo mini-plug on one end. The PA-331 is included to convert to a monaural 3.5mm input. The PA-231 is included to convert to a 2.5mm monaural input.