When we re-homed our 2nd set they came with 2 of these, or something very similar at least:
Here is a link to them on Exotic Nutrition. http://www.exoticnutrition.com/newnomefest.html
The 2 girls that had them seem to love them. Since we haven't been able to get all 4 of our gliders in the same cage yet, I can't say if the other 2 would use them.
But, we also put some kind of ceramic dish inside of them, like this:
Here is a link to that, but I just picked some up at a local pet store as well: http://www.exoticnutrition.com/cefedisallsi.html
We also use these with our 1st set of re-homes, again it is what they came with, but we like them. We tried some stainless steel ones and while they are great, they were just too light and would tip over when the girls tried to jump on them to perch and eat.
Now we use the stainless steel ones only with the ring that attaches to the cage, and we put their liquid staple in them.