This is the 0.75mm adapter for the TRN BT20S Pro bluetooth system. It fits basically all compatible IEMs and offers the same level of Bluetooth quality as other adapter types. I recommend this product if you have multiple IEMs you want to use with different pin requirements, as these adapters are very affordable once you have bought the battery piece with charging case.
I bought this adapter to be able to use a pair of custom IEMs with the TRN BT20S Pro. Unfortunately out of the box I couldn’t do this because the adapters were not compatible with the recessed plugs on the IEM, but with some minor precision surgery to the adapter I was able to make it happen. This system of interchangeable adapters is fantastic and I look forward to TRN potentially adding more adapter types to the range. ***Please note all pics shown are of the adapter post-modification.***