wow this cover i got for a discount price, Is great!!!the heat and humitity stay in great if you Cover 3/4 of it with Clear plastic. i got it at petco for $7 it was $25.00 Comes with Sure-Lok Clips to keep it in place (No excaping hermies) Come for size's 10gal, 20Long Gal, and 29 gal, and maybe 30gal.
Also works great for Small Furry Animal
Also heres a Pic of mine with the plastic on.