Amazon®: SE 5Piece Set of Patented Stackable 13¼ ...
Each litter box holds an entire plastic container of litter. Scooping out the boxes with a hand scooper used to take quite a bit of time and kicked up so much dust in our house. Now, I use both sifters together, on top of a 5 gallon bucket outside, and pour the entire dirty litter box through.