If the dimensions are as you say and it is diameter and not circomference, it would be suitable for snakes up to 2' to 2.5' long. I know you're getting your setup ready and that's great, but you might want to just find a nice oatmeal box or cool whip container or something until you have the snake and can better guess what size will be a nice snug fit. He'll need hides and they should be dark and snug but they don't have to be anything fancy unless that matters to you for appearances but even so it would wait until you've passed the first week of leaving the snake alone to provide new hides.