Do you work for an equipment OT store?
These aren't the best, the seat doesn't have any slip resistance so can be dangerous and aren't idea in modern acrylic baths. Your better off getting a bath board that sits on the top edges of the bath and pressure fits to the sides. Or a proper non stip stool, like a the Invacare cadiz.
This is only £13.79 if you have a chronic medical condition. If you don’t you need to add VAT on top.
I never recommend the use of these in an acrylic bath , I've seen a weighty person put the feet straight through one.