How we rate compatibility

Every accessory carries two signals, not one: whether it physically fits your machine's group, and what evidence backs that.

Fit - does it physically fit?

• Confirmed fit - manufacturer or manual confirms it. We reserve this for verified machine facts, never a marketplace listing.
• Fits the group - the part's size matches your machine's portafilter group. The size is a real, checkable fact.
• Size not stated - the listing lacks the size or model data needed to judge.
• Wrong size - the size does not match the group head; it will not seat or seal.

Evidence - how do we know?

• Manufacturer-confirmed - stated by the maker or the manual.
• Seller says it fits - a marketplace listing claims compatibility; we label it as a claim, not a confirmation.
• Inferred from size - the size matches the group, but the listing makes no compatibility claim.
• No fit info - not enough data on the listing to judge.

A marketplace listing can show a green “Fits the group” chip - because the size is a fact - but only manufacturer or manual sources reach “Confirmed fit.” We do not physically test products. Tampers and distributors are sized one millimetre under the portafilter (a 53mm tamper fits a 54mm Breville group). Always verify size against your machine before buying.

Report a compatibility issue

Every product card includes a report link with the page, machine, ASIN, category, and current verdict prefilled. Reports should be reviewed before changing a product's category, decision-table rule, or placement bucket.