Isn't your boy a syrian? If so, he'll need at least a 10 inch wheel. Unfortunately, Silent Spinners only come in 4.5 inch, 6.5 inch, and 12 inches. I think most pet stores here in the US sell comfort wheels that are 8 inches, but many Syrians will outgrow an 8 inch wheel (mine certainly did lol)
Wodent Wheels come in 8 and 11 inches, and are very popular for Syrians, though they're a bit tricky to clean.
My personal favorite is the Carolina Storm, which is about 10.4 inches and spins completely silently
