Today we were informed that our unique top entry design was granted a U.S. Patent number D1103509. It's been over 5 years since we envisioned the great advantages that this disposable cat litter box provides for both cats and cat lovers. Top entry and side entry, open or enclosed. It has almost endless possibilities in feline litter box care. We tested it over and over with our own lead tester Sassy Cat. We pushed the box to 8 months on the same box with zero leaks on three different occasions to make sure that it would withstand the use and it exceeded our expectations. We are proud to offer it and want to give a special thank you to all the customers who have believed in it and used it over and over in the past five years. Cats Desire Disposable Litter Boxes.