The TV box thingy is like a "normal" Bluetooth transmitter for a TV, the only differences are that my mom's one has direct RCA and optical instead of an audio jack and a blue led to show it is powered and a brightish orange one to show if the connection is active, here it is:

https://www.hab.online/product/oticon-connectline-tv/

The neck thingy is this one: https://www.hab.online/product/oticon-streamer-pro/

The above (UK) site seems to have all versions of these thingies, here:

https://www.hab.online/product-category/wireless-and-remotes...

The alternative:

https://www.hab.online/product/oticon-connectclip/

we tried but it is too small for my mom to use comfortably.

Here is the manual of the streamer, with more details:

https://www.oticon.com/-/media/oticon-us/main/download-cente...

Check also this:

https://www.ndcs.org.uk/information-and-support/technology-f...