We had to get a second, bigger crate (XL, 48") for our 5-month old German Shepherd pup, who will grow to be more than 80 pounds. She has already outgrown the Size L crate we borrowed from our Australian Shepherd. Now she has her own crate and enjoys eating and sleeping in it. I like that the door closes by lifting then lowering it into a track, then locking the bar--so the cage is doubly secure. So far, the bars are holding up to chewing and pushing.