I have had a number of different styles of litter boxes other the years and this is THE VERY BEST TYPE!!  Thank you so much Arm and Hammer for developing this style.  I can clean out the cat waste 3 times faster then any other style I have had and with no mess.  The OTHER GREAT thing I also love is that the interior sides and bottom are smooth.  No crevices or small indentations in the design that make it real tough and time consuming to clean out!  Love it!  Love it!  Love it!