I think boas do a little better in the "bigger" enclosures than ball pythons, so the medium might be okay. I keep mine in a 34 qt tub right now (not sure of the dimensions) and he has two hides in it. He is ALWAYS in his hides...but I've heard most boas don't even use them. Anyways, I think if you wanted to go with the medium it would be okay, however I'd not spend a ton of money on a custom smaller enclosure since when he/she gets full grown you will need a much larger one, preferably with a lock lol. If you have the extra money than go for it, but I don't which is why mine gets a tub lol. I have time to save up for my 4' enclosure![]()