This is a set of four Reehut yoga blocks, something like this https://www.compleowaco.com/shop/physical-therapy/reehut-yoga-blocks-1-pc-2...
They arrived when we helped out eldest clear his house and emigrate; we just found them again, and we still don't want them. :)
Yoga blocks (Winnersh RG41)
This offer has been gifted to someone and is no longer available.