This post is for all the kitty sisters........we started using these sterlite or rubbermaid containers years ago for our kitties that feel they need to stand and spray when they pee, well, we had to graduate to these 20 inch tall ones, I discovered Cassie was sticking her rear in the air when she pee's and the spray was going beyond the 13 inch tall boxes, and hitting the wall......thank heavens I saw her doing it and was able to resolve it quickly......I couldn't yell at her, after all she was in the litterbox.....I don't like the covered boxes as they are too hard for me to sift....anyway, in case any of you other cat lovers have a sprayer in the house, this is a pretty inexpensive solution.....