Fit check
The fit check answers the only question a parts shopper really has: does this part fit my job. It compares the shopper's active finder answers and filters (the constraints) against each product's specification record, and shows one of three states.
The three states
- Matches your project. Every active constraint that has a corresponding specification field is satisfied. The panel lists the matched specifications, so the shopper can see why it matches.
- Check specification. The product has no value recorded for one or more active constraints, so a match cannot be established. The panel names the missing specifications. This state is deliberately not a match and not a rejection: it is the theme saying the data is not there to judge, which usually means the product record needs completing (or the shopper should read the datasheet).
- Does not match. At least one recorded value contradicts an active constraint. The panel names the conflicting specifications and the values involved.
When no constraint is active, no verdict shows. The product page fit panel instead invites the shopper to add project specifications, with a link back to the finder.
How the comparison works
- List fields (thread and standard, material, compatibility, compliance) match when any value in the product's list matches any value the shopper chose. Comparison is case-insensitive.
- Number fields (primary dimension value, primary rating value, pack quantity) match on equality for value-list filters. When a filter carries a minimum and maximum, the value must fall inside the range.
- A constraint on a field the product leaves empty produces Check specification, never a silent match. The theme would rather admit missing data than invent a fit.
- One conflict is enough for Does not match, and a conflict outweighs matches on other fields.
Where the states appear
- Product cards, in collection results and search results, when Show fit state on product cards is on (it is, by default). Card verdicts use the constraints active on that page.
- The product page, in the Fit check block of the main product section. The block shows the full reasoning: matched specifications, missing specifications, and conflicting specifications, each under its own heading. It can also show the product's specification summary. Where the panel gets its constraints from depends on how the shopper arrived: opening a product from finder results carries the finder answers across, so the verdict on the product page is about the same project as the results page.
- The finder context bar, which keeps the active project visible above results so the verdicts on the page have a stated context.
Fit states and colors
The three states have their own color pairs in Theme settings, under Colors, then Fit state colors: Match, Check specification, and No match, each with a background and a foreground. The shipped pairs are contrast-checked. If you change them, keep body text at a contrast ratio of at least 4.5 to 1; the states carry meaning, and shoppers with low vision still need to read which state a product is in. The state is always written in words as well as color, so color is never the only signal.
What the fit check never does
- It never invents data. The theme does not read titles, tags, or descriptions for specifications, and a product with an empty record gets Check specification or no verdict, never a guessed match.
- It never blocks a sale. A product in any state, including Does not match, can be added to the cart. Fit is advice with its reasoning shown, not a gate.
- It never phones home. There is no external fitment database and no live lookup. Every verdict is computed from the record you entered, on the page, which is why keeping the record accurate matters more than keeping it long.