Rear Car disc hub? help idenitfying

Hey peeps! I've come across these. Really weighty, I was going to scrap them but not sure if they're any good to offer up on social media. I've tried Google but it really isn't helping. They look heavily used and ife not a clue about car parts.

The details on them are B6 Pagid 55529 then underneath it says 90R-02c0428/1714.

Really just trying to find put if they're good for someone or for the scrap heap. Cheers