True wireless adapters


(if this is not the right forum please move)

I am looking to make my Mangrid Tea IEMs truelly wireless. Those are two pin. What options are there?

Saw a Z review of some expensive Fostex (?) with annoying buttons, Fiio solution is known to disconnect.
Is there anything else out there?

I dont want a neckband like thing. Dont really undestand its advantage over something like a Fiio BTR5