Adapter: 1 x 3.5 mm mono socket to 1 x 3.5 mm stereo jack plug

Adapter to convert a monaural signal into twin channel (stereo) output

For attaching a monaural microphone to a stereo recorder so it records on both channels. e.g. To use an Olympus ME15/ME52W or CM909 tabletop microphone and with Olympus WS range recorders