"Advance" are Specsavers "home brand", which is a rebadged...

"Advance" are Specsavers "home brand", which is a rebadged product supplied to Specsavers by one of the big hearing aid manufacturers. Another term for this arrangement is a "white label" product. Given Specsavers' brand recognition in this retail space is much stronger than Nuheara's it's not outside the realms of possibility that Max or future NUH products could be made for Specsavers to sell as part of their existing "Advance" product range.

Edit: "Specsavers’ exclusive range of Advance hearing aids are produced by leading brands such as Siemens and Unitron"