Open-top~$550PetSafe
PetSafe's open-top design has no hood and no globe, so the cat never walks into an enclosure at all. Its user guide is unusually specific about kittens: keep auto-clean off until the cat is both 3 lb and 6 months old, because the trigger is a weight change of more than 3 lb. PetSafe rates the bowl for cats up to 33 lb and puts the drawer at 8.5 litres.
Approx. price
~$550
maker's store, not a live price
Best for: Large or hood-shy cats in a home that uses clay clumping litter
PetSafe says the sensor detects cats from 3 lb and sets a minimum age of 6 months. At the usual rate of about a pound a month, that means leaving automatic cleaning off until roughly 6 months. Below the threshold, a kitten may not register at all, and the box could start a cycle with it inside.
Detection: weight, infrared / radar. The maker does not state any anti-pinch protection.
How minimum weights work, and what to do below them8.5 L ÷ (cats × 0.7 L a day). The maker claims up to 14 days for one cat, within reach of the arithmetic. Where 0.7 L comes from.
The two lists above are drawn from the maker’s own pages, manuals and prices, not from owner reports. Where owner discussion has been read it appears in its own section below, so the two are never mistaken for each other.
No owner discussion has been read for the PetSafe ScoopFree OpenSky yet. This section stays empty until there is something real to put in it.
Open-top
Best for: Cats that avoid enclosed boxes, in a home that wants a big drawer
Open-top
Best for: Cats that want a flat open tray, in homes with room for a long unit
Open-top
Best for: Large-breed households that want an open box