M
Heavy but very sturdy construction
Looks Like Furniture
The box this came in was incredibly heavy at over 45 pounds so make sure you have help moving it. Assembly took a minute because there are eighteen structural posts in total to keep track of but the instructions were clear enough. Once it was up I was happy with how solid it is. The dual foundation makes it really stable even when my cats are playing rough. One star off just because of how heavy the master carton was to drag inside.