I realized that the 20 x 26 inch layout is backwards. A cat enters on the wide side. So the cat is standing in a 20 inch length from head to butt. Cats don't turn and do their business sideways which is 26 inches wide. My cat is arthritic and stands when she urinates. She needs a longer area. The 20 inches is the same as the length of a regular litter box. She urinates in this box and it goes over the shortened area and onto the floor. Might be fine for multiple cats but the size does help arthritic ones.
This box would have been perfect except the sides and back are only 5 inches, while the low entry is superb for my senior cats, you need to compensate with the back being higher, to catch any urine or etc that gets dropped from a higher height. I really wish this company made the perfect box for us. This one is only almost perfect.
Sadly, my 18 year old kitty only uses this for his stools. He still thinks the cabinet is a great place to pee. The box is great and large and easy to use but try to convince him of that.
Definitely way bigger than I expected. Large enough for a dog...not that dogs use litterboxes.
This helped my senior kitty immensely, as he had increased health issues, including blindness. He started using us right away.