Model differences
PETKIT Crystal Duo open entry or front-entry hood?
Within the PETKIT Crystal Duo family, the important entry choice is not a different rake or litter system. The open U.S. options are T7 (white) and T7-G (gray); the separate hooded listing is T7-W1. PETKIT identifies the powered box in the family as P9905 and the compatible front-entry hood as P99051. Choose the way your cat approaches the tray before comparing camera features or exterior style.
The shared cleaning plan
The uncovered T7/T7-G base has an open-top tray; T7-W1 adds the P99051 front-entry cover over that same P9905 powered rake, side waste traps and PETKIT crystal tray. None uses an enclosed rotating-globe method. The P9905 manual requires PETKIT’s Crystal Litter Set with the matched tray and rejects other brands or litter types such as clay and tofu. The hood does not make the Purobot compatible with ordinary clumping litter. If crystal supplies are not practical or the cat will not accept them, this family is the wrong starting point; compare models built for the litter you already use.
The maker says the hood fits the Crystal Duo without blocking the rake or affecting automatic scooping. The exact T7-W1 package diagram shows a main unit and one hood along with the camera, installed tray, crystal litter, N60 odor eliminator and setup accessories. The hood is thus an entry/containment change, not evidence of a second cleaning mechanism. The tray still has to be removed and replaced, and solids still collect in side traps that need routine attention.
Open entry or front-entry hood?
Choose T7/T7-G if your cat uses open trays, you want to keep the route visually open, or you do not want a large cover to clean around. Select T7-W1 only when the front-facing hood is a feature you want—for example, to create more separation between the tray and the room or to help catch kicked litter. PETKIT advertises containment and odor benefits, but those should be treated as intended benefits rather than measured guarantees. Cats can also have their own preferences about enclosed approaches, so do not switch a cat that rejects covered spaces just to gain a shell.
The questionnaire reflects that difference: choose crystal litter plus an uncovered entry for the T7/T7-G; choose crystal plus front-entry hood for T7-W1. Selecting app reporting does not change the hood decision, but it adds a separate requirement: PETKIT lists 2.4- and 5-GHz Wi-Fi and says the app must be bound before first use. The camera can be disabled in settings; full video-history features may require PETKIT Care+.
Measure conservatively
The hooded P9905 page lists the box dimensions as 32.20 × 19.96 × 13.14 inches and an entrance-height value of 7.08 inches. The separate P99051 hood page lists 29.13 × 16.45 × 12.59 inches. Neither page labels the dimension axes, and the second sequence is the hood component, not a guaranteed combined floor footprint or final mounted height. The exact clear opening through the fitted hood is not separately listed. Keep width, depth, assembled height and cat passage unknown for hard fit filters unless you verify them from current manufacturer information.
The base manual limits use to cats at least six months old and over 3.3 pounds; it lists no upper weight or rated household cat capacity. Those limits apply to choosing either entry version. The tray life claims also vary within the product page, so the stated “up to” period is not a reliable calendar promise. Think of the hood and open versions as the same crystal-tray ownership commitment with a different entry environment—not as a capacity upgrade or a solution to every tracking or odor problem.
Alternatives when the answer is “neither”
If you want a front entry but need clumping litter, compare a front-entry rake model that explicitly supports that litter. If you want an open top with ordinary clumping litter, compare a sifting design rather than trying a different granular filler in the Crystal Duo. And if exact passage dimensions or multi-cat capacity are essential, use a model whose manufacturer publishes those limits. The current PETKIT open listing, T7-W1 listing, and P9905 manual are the right places to check exact package and care details before ordering.