Check out spinzone products, they have some neat products. Also stealth wheels
are highly recommended.
The mesh in the wheels
is really nice. It allows their pee and poo to fall through into the bottom of the cage as opposed to just splattering around on the inside, possibly dripping onto your gliders
Before I did all the research I purchased the wodent wheel. It does have the center post, but has now been revised to have it covered to protect gliders tails which may get caught. This stock wheel is not silent and has the solid track. I did not like that...excrement was easily caught in grooves and stunk quickly. I have since modified it to have a mesh track which in my opinion is far better and easier to clean and manage. I also changed the mounting to be a cage mount and used some fleece as cushion on the new way I mounted it and now it is nearly silent. When I purchase another wheel, it wont be this kind. Probably a Spinzone or Stealth product.
Hope this helps.