The first time I put my cats in they kind not like it but doesn't took long for them to adjust and get used to it. I have two bigger cats and 2 kittens and they all perfectly fit in it. My two kittens love the hammock but my two big cats never used it. Assembly I able to do on my own and probably took me 30-45 mins to finish. Overall very satisfied with my purchase. Now I can contain my cats if I'm not around and let them out and play if I'm home.