Important.... on some telephones the contacts are in reverse order. If you don't hear anything in the headset, simply swap the plugs (microphone and headphones) then it works. Note: Only suitable for analog or ISDN telephones and not for IP telephones. These are digital telephones. (for example, it doesn't work with cisco ip phones). unfortunately this is also the case with some normal telephones. The adapter that you will get from us is the standard version and works at approx. 95% all phones. On some telephones (ip), however, the PIN assignment other. This means that the small wires (4 small cables) that are in the plug of the telephone receiver are sorted (occupied) differently than the standard. If the person you are talking to can hear you well, but they cannot hear you well enough, t.
