Looks like one of those Hoover power nozzles that came with the Futuras and the Powermaxs. The off-centre wand neck is quite unique to that Hoover design from the early 1990's.
Yes, it's my belief too that Hoover and Thermax had some sort of deal. The past few power nozzles of theirs have resemblance to Hoover Futura/ PowerMax style.
Yours and the green one are very close to the non-headlight Hoover Futura/ Encore Supreme power nozzle. I believe the brush rolls may even be interchangeable.
See attached photo of the Hoover PowerMax Plus S3520 which has the power nozzle I'm referencing.
The eBay auction for this older Thermax nozzle is essentially an exact copy to my Hoover PowerMax power nozzle. I have 3 PowerMax nozzles and this is one of them in the 2nd and 3rd photos!