Review on Optimized Catit Design SmartSift Replacement Liner for Enhanced Cat Pan Base by Beth Watson

I use these bags for the bottom liter box. It's the best self sorting out there. There are no motors to break or clog. Just a pen. I leave the top open as it gets stuck when closed, but the lid is pretty sturdy. The only downside is if the screen plate swivels don't come back properly after a complete liter change, the liter goes under the bag. So you need to make sure this is assembled correctly.