These are the Rodipet ones
There are two different prices for each size of wheel because some come with a custom shelf for them to sit on (to raise them and make a hide underneath). They're not cheap! Even without the stand. The 27" one works out at about £36 and postage is another £8 ish. They are silent but unless you need one that extends in height, one of the other two silent wheels would be cheaper. I do have the 21" one for our robo.
https://www.rodipet.de/shop/laufraed...n-korklaufrad/
The Trixie wood one at £10 ish mentioned is silent. I have the 12" Silent Runner for our Syrian. It's an excellent wheel- costs more at £25 but it's safe and sturdy and mine has been going for a long time without any breakages or problems.
Either of the wood/cork ones you would want to paint with plastikote in case they get pee'd in or on (which is very likely!)
Don't get the Silent Runner from Rodipet though - it's cheaper to buy it in the Uk and the postage is less.
Silent Runner 12 Inch
This is the Trixie silent one
Trixie Wooden Exercise Wheel | Free P&P on orders £29+ at zooplus!
You can paint both the cork and the wood with a couple of coats of plastikote - this one - it's water based and safe for pets. Doesn't really smell of anything.
https://www.amazon.co.uk/gp/product/...?ie=UTF8&psc=1