A peaked roof prevents water from accumulating on the house, opposed to a flat roof that lets water collect.  Just like the roof, the Litter-Lifter's uniquely-shaped peaked blades allow litter to slide down their slanted sides back into the box; unlike old-fashioned scoops with flat tines that cause litter to collect on the surfaces.

The Litter-Lifters don't scoop up clean litter. They only LIFT out waste.
It's all in the peaked shape. 

No Clogging - No Shaking - No Dust