Large enough for my big boy tomcat.  Comes fully assembled, which was great!  The only thing I would change is to add a bit of padding under the carpet, but most come without it, so it’s not a surprise. I lay a folded fleece baby blanket on each perch, which makes cleaning even easier - I just switch out the blankie for washing and then I don’t have to vacuum it as often.  Fits under the window and my kitties love it!