Here's a clip from a DIY School Hearing Aids (v2.2) PDF file named (Noahlink Wireless - DIY User Guide)
Noahlink Wireless 2 (circa 2024-Q1) uses a modern USB-C connector cable and provides support for Bluetooth Low Energy/BLE 5.3 (vs the older BLE 4.2 for Noahlink Wireless). Noahlink Wireless 2 devices are not yet widely available or easily purchased (as-of 2024-Q2).
DIYers should just keep using the older/cheaper Noahlink Wireless until we find substantial benefit for using the new BLE 5.3 wireless protocol, or substantial benefit for using the new modern USB-C cable.
Note of caution: There is still no Apple ARM driver available for Noahlink Wireless (and also for Noahlink Wireless 2) so this still cannot be used for newer ARM technology (Apple silicon) based computers (even under emulation).