Can anyone recommend a wobble seat for a dc with ADHD?

[bodiddly]

I started looking at these for ds and wondered whether you get what you pay for or whether a cheaper one would be ok. Can anyone recommend a particular brand/supplier? Thanks

Bump

DS2 had the move'n'sit one at school, but we needed one at home and that was beyond our budget, so we bought one for less than half the price from physioroom. It does exactly the same thing.

Thank you both - I will have a look!