Photos attached to the confirmation. No finger part number, which is now looking like an expensive omission. Our little plastic samples are in the trial photos too.

Then refer them to those attachments. Ask whether they will supply the photographed set or propose a documented substitution for review. A missing part number does not make their alternative proven suitable.

Thanks Mina. I'd been trying to make them admit it was different. They already have, really. It's getting the agreed set or an actual proposal that's missing.

Yes. I would also ask who will handle the technical comparison. You need someone who can discuss your samples, not another sales reply repeating the same adjective.