The headset adapter from Good Connections® allows you to use your conventional headset with two three-pin 3.5 mm jack plugs on your smartphone, tablet, notebook and many other devices with four-pin 3.5 mm jack socket. For easy connection, the connectors are color coded. Pin assignment according to OMTP standard The four-pin jack connector of this adapter is assigned according to the Open Mobile Terminal Platform (OMTP) standard. According to this standard, the connector is assigned as follows from tip to shank: https://elecena.pl/product/20041578/ad-hs03-audio-cable-3-5-mm-jack-plug-to-2x-jack-omtp-0-2-m 2022-01-09 https://elecena.pl/product/20041578/ad-hs03-audio-cable-3-5-mm-jack-plug-to-2x-jack-omtp-0-2-m 2022-10-05