size wise, they are fine for gliders.
The feeder doors would need ziptied to secure them.
The cages are made with thin, flimsy wire. Which will rust sooner than heavier cages and are also a lot louder than heavier cages.
Also keep in mind the weight of glider safe wheels and their wall mounts sometimes the bars on flight cages like this break where the wheel is mounted.
They are "ok" cages, but for about the same money you can get a brisbane cage that is heavy duty, quiet, and will last longer and won't need replaced as often.
Considering the life span of gliders, a quality long term cage is more cost effective than cheaper made cages that need replaced more often.
http://www.exoticnutrition.com/Products/Brisbane-Cage__GA13221A.aspx