Questions about equip USB C - jack 3,5mm

The jack of the adapter is not explicitly described as 4-pin. Normally, 3.5mm jack adapters are either 3-pin (for stereo audio) or 4-pin (for stereo audio plus microphone). Without specific information about the number of pins, I cannot confirm whether this adapter is 4-pin.

Thanks for the hint. :)

Sorry to disappoint you. Just tested it by making a phone call. No sound was heard.

I can only assume, but I would guess that the DAC chip (= active adapter) built in according to the manufacturer is only designed for headphones and does not recognise your end device. It's better to buy a USB-C to cinch adapter that is really designed for hi-fi use. Otherwise, the sound quality will certainly not satisfy you.

Is a 3.5 socket whether the trs has no plan

Unfortunately, the manufacturer's page is not very informative either 😅 https://www.equip-info.net/equipinfo_en/productpdf/download/file/id/10758/name/133474_USB-C_to_3.5mm_Audio_Adapter.pdf/