Lets talk about the litter box system itself first. The Ugodog dog litter box is made of sturdy material that can handle a great amount of weight. What sets this system apart from other ones is that its grates are specifically designed to be kind to sensitive doggy paws. The way the grates are made is specific as to not cut the bottom of the paw pads. Also, the openings are small enough so that even the tiniest dogs will not get their paws trapped. The grates also are two separate pieces to allow for easier clean up. This system is eco-friendly, durable, inexpensive and no replacement parts needed! That is why this is my pet potty pick.