Since the LX50 is primarily intended for use on PC and current game consoles (PS4, Xbox One), it uses the CTIA standard 4-pin connector of the shorter cable.
Some older Nokia, Android and Apple devices use the less common OMTP standard. If you want to use the single 4-pin mini-plug to connect to these devices, you will need to purchase an adapter from CTIA to OMTP. The adapter can be purchased in stores for a few euros.
The LX50’s extension cable uses a separate microphone and speaker port, making it compatible with all popular PC sound cards as long as they provide separate ports.