A roller box rotates its inner drum to tip clumps into the waste drawer. Cleaning coverage tends to be more complete, but the body is bulky and needs generous entry space.

A rake box pushes clumps into a collection bin with tines. The body is usually more compact, but it is more sensitive to litter type and clump strength, and a jam needs manual clearing.

Multi-cat homes should weigh waste-drawer capacity and identification method first; single-cat homes can put noise and cleaning convenience ahead.

Both need periodic deep cleaning and consumables. Treat any maintenance-free claim with scepticism, and include after-sales response in the decision.