This is a great alternative litterbox that was not primarily designed to be a litterbox. It's actually an industrial stainless steel steam table pan. Yep, this "litter box" was made to prepare and serve food!
Stainless steel seems like a no-brainer material for a cat toilet. I mean, it's stainless! Metal boxes are easy to clean and won't retain odors. This box is very close in dimensions to a large standard litter pan you'd find at any pet store. The box measures 20.9" by 12.9" by 6.1". The pan has a small outer lip that is curled under at the edge, so it's safe for your cat to enter and exit. The strong box is also surprisingly lightweight, making it easy to work with and clean.
Alternative use product alert! One of our kitties (it's William) has a thing for chewing on wires. He especially likes Apple product wires and other similarly pliable round cables. They're his favorite thing and he's already chewed through several iPhone chargers and even our Amazon Echo wire! William is the reason we couldn't play Christmas music in our living room on Christmas day. We tried a few options and found this great solution: split loom tubing.
What do you look for in a litter box mat? It's got one main job: to keep litter from scattering all over the place. It would also be nice if it didn't clash with its surroundings, and it fit snugly in the space it needs to fill. Instead of buying a "litter box mat", which may or may not fulfill any of these criteria, consider using a yoga mat!