@ReeceBaker0471 Yes. Their prepayment reply references our drawing, and the delivered identifier differs. My unpacking photos show the interface difference before we've fitted anything.

Provide those records together and request an interface drawing specific to the configuration you received. Keeping the tooling off preserves the original condition while its compatibility is assessed

Is the suffix enough to call it the wrong revision? I don't want the whole conversation derailed by what one letter means.

@NoraAllen0322 Call it a configuration discrepancy. Quote both identifiers and show the visible interface difference. That gives them two concrete things to explain.

If the interface drawing matches your fixture, that would establish compatibility. Ask them to supply it rather than repeat 'equivalent'

@ReeceBaker0471 The interface drawing could address physical fit, but it wouldn't by itself establish compatibility for all connections and application requirements.

I overstated what that document would establish. The drawing can help resolve physical fit, while the remaining compatibility questions need assessment against your intended configuration and application

Is this possibly only a labelling change, despite the visible difference in the interface?

We don't know what the suffix signifies. But your visible interface mismatch still needs an explanation, even if the label change turns out to be harmless

The configuration comparison has been completed, and qualified review supports the supplied interface for our stated fixture requirements. I've accepted it on that limited basis; installation checks remain.

That gives your acceptance a defined scope. The remaining installation checks still matter