This crate is gorgeous! When we first received it Bob was 34 pounds and 3 months old. Bobby is 6 months old 51 pounds now and the medium is still big enough. And from what I can tell will be fine for the rest of his projected growth. He has room to stretch out. I leave the door open and he’ll go in just to take a nap. Super grateful this thing exists. The clear lucite door fits in beautifully with the rest of my vintage furniture.