Rotating drum~$800PETKIT
Unlike PETKIT's other drums, the Ultra bags its own waste: each full load is heat-sealed from a refill ring, so emptying means lifting out a closed bag. That convenience makes the ring mandatory, which is why this is one of the few clumping-litter boxes here with a required consumable. The 10-litre bin is rated for up to 20 days with one cat, and 20 sensors plus a camera watch the drum.
Approx. price
~$800
maker's store, not a live price
Best for: Owners who most want never to handle an open waste bag
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PETKIT says the sensor detects cats from 3.3 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, camera. The maker states anti-pinch protection on the moving part, by sensor or by design.
How minimum weights work, and what to do below them10 L ÷ (cats × 0.7 L a day). The maker claims up to 20 days for one cat, which is more generous than this arithmetic supports. 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.
The Ultra's self-sealing bag system is what sets it apart, and it is also what owners argue about. Emptying means lifting out a closed bag, which owners who have handled open drawers appreciate, and three owners found smell better contained than their previous box. Against that, one owner says the sealing fails more than half the time, and another found odour between emptyings worse until they changed the cycle delay.
Day to day, owners describe a large, well-built machine with an app that gives more control than Whisker's: manual cycling, a live view of the drum and a mode that rocks the drum to cover waste. The camera's full recordings need the Care+ subscription, which two early buyers only discovered after setup, and a few report playback problems and features still marked as beta.
Where it makes sense is one or two average-sized cats, in a home that values never touching an open bag and accepts buying PETKIT's refill rings. For a Maine Coon or another heavy, tall cat the drum is the constraint: one owner would not recommend it for a Siberian or Maine Coon. One buyer who weighed it against the Max Pro chose the Max Pro for its smaller size and price.
When you empty it, usually yes, because the bag is sealed before removal. Between emptyings, one owner with both first thought the Purobot Max held odour better, then found that shortening the cycle delay fixed it and now smells nothing.
PETKIT rates it to 10 kg (22 lb), but a pet-sitter found a fluffy 16 lb Ragdoll looked cramped with its head out of the entry, and an owner's 5.2 kg tabby sometimes pees over the edge.
Live view works without it, but one early owner found that playing back recordings, downloading clips and getting unwatermarked pictures need Care+ after the trial.
PETKIT's 20 days is for one cat. An owner with two cats using the box seven or eight times a day packed and refilled it about every five days, and a pet-sitter with two cats had to pack it every five or six days or it stopped cycling.
One owner left it unplugged and then in Kitten mode for the first days, and another rotated the camera to face inward so it did not move, which got three of their four cats using it. Others suggest leaving the old box beside it without cleaning it so the Ultra becomes the cleaner option.
Rotating drum
Best for: Multi-cat homes that need cats told apart and can live with a 22 lb ceiling
Check price on Amazon
Rotating drum
Best for: One or two cats under 22 lb, especially older cats that struggle with a high step
Check price on Amazon
Rotating drum
Best for: Large multi-cat homes that want visit-level tracking without a camera