Bought the medium, probably should have gotten the small for my cats who enjoy being on the deck during the summer.
                    The frame is metal with heavy duty plastic connectors. The fabric is a heavy quality nylon material, much like the fabric used in luggage & back packs and is well stitched.
                    It may be a little difficult to get the last corner connector in, but it will fit, it will be uneven when first set up, but once your cat or dog gets on it, it will straighten out.
                    Because I needed to take it apart for winter storage, my husband grabbed on corner connector, I grabbed the opposite side connector an pulled slightly while turning it, it came apart and all parts are now stored for summer usage. This may help someone who has to replace the cover should it become worn or damaged by your pet.