Model comparison
BISSELL CleanWell 4393 vs. Neakasa M1 Plus vs. PetSafe OpenSky
These three products all offer a view of the litter chamber from above, but “open top” does not mean one identical operating plan. The CleanWell 4393 and Neakasa M1 Plus are open-top rotating sifters for clumping litter. PetSafe’s OpenSky also has an open top but its entry shape is a distinct rotating chamber/globe, with different published app and weight boundaries. Choose among them by the actual opening, automatic-mode limits, litter and the app detail you need.
CleanWell 4393: app alerts, but confirm the fit details
BISSELL’s exact U.S. product page identifies model 4393. Its manual requires clumping litter and recommends two to three inches between the fill marks; the support FAQ gives outside dimensions of 26 by 21.1 by 24.7 inches. The manual says cats below 2 kg or above 15 kg should not use it, and BISSELL support says not for kittens six months or younger. The product page lists app use/waste alerts and a magnetic OdorVault bin seal. One-cat waste duration is inconsistent across the page (up to 20 days) and guide (up to 21), so plan on checking and emptying by the bin’s actual fill, not traveling around that headline.
The product page says 25.1 pounds while the official FAQ says 23 pounds. There is no confirmed 4393 entrance width, cat-count rating or app Wi-Fi band in the reviewed U.S. sources. An app requirement may be matched; a required 2.4 GHz or 5 GHz band should remain unconfirmed unless BISSELL clarifies it. Read the CleanWell 4393 assessment for more on the movement, transition and drum maintenance.
Neakasa M1 Plus: package choices and a different minimum
The M1 Plus also suits an open-top rotating-sifter preference and clumping litter, with app access. Its exact listing gives a lower automatic-mode weight guide of 2.2 lb and an upper guide of 33 lb. The current U.S. selection has multiple packages: base, a step, an AirStep package, or a fence package. Do not read those add-ons as the same configuration. The maker’s listed body dimensions conflict with related diagrams, so the height/width/depth hard-match fields remain unknown; Wi-Fi band and numerical household capacity are also not confirmed. Compare package contents if an access step is essential.
OpenSky: distinguish the top opening from a sifting tray
OpenSky is an open-top rotating chamber with app activity records, but unlike a wide exposed pan it still has a moving sifting chamber. PetSafe documents most clumping litter, 2.4 GHz app connectivity, an 8.5-liter drawer, a 3-pound sensor change threshold and a 33-pound upper guide; its manual says cats should be at least six months old and three pounds for automatic use. PetSafe gives a one-cat emptying estimate of about two weeks and separate guidance for larger households, but no numeric cat capacity is used in the matcher. Its lower weight threshold is lower than the CleanWell’s, while the Wi-Fi band is actually specified. The OpenSky article explains the threshold and litter caveats.
A practical decision
Start with the youngest and smallest cat. A cat below the CleanWell’s manual weight limit or at six months does not meet BISSELL’s automatic-use guidance; a lower-weight pet may fit another documented plan, but check that model’s age limit too. Next decide whether “open top” means a rotating sifter or simply a shallow uncovered pan. Then ask whether an app is essential, whether an exact Wi-Fi band is required, and whether the package must include an approach step. If a needed number is not published, leave it as unknown instead of guessing from a product photo. See the full buying and ownership guides and the individual assessments before comparing any current package or seller.