I have this one for Steve, it is 5.9 gallons. It's heated and has a heater.
EDIT: LOL, that sentence was completely incoherent. What I meant was that it has a heater and it filtered. Also, I wanted to add that the lid doesn't allow for a HOB, which is what I have, so I've had to create a lid myself. I also have found that many kritter keepers scratch easily. I actually ruined a whole side of my keeper the day I got it by using eucalyptus oil to remove tape residue. I'd just go with a glass tank, to be honest.