Check the supplier's registered company identity, business contact details, written quotation and payment beneficiary. Require the exact brand, complete part number and suffix on every document. Ask for real product and label photos, inspection information, written condition, warranty and return terms, plus a traceable shipping plan.

Provide the installed label, complete suffix, hardware or firmware details where relevant, electrical data, interfaces, terminal arrangement and application requirements. A responsible supplier should raise compatibility questions instead of treating a similar family code as automatically interchangeable.

Be cautious when the quotation omits a legal company identity, the requested suffix changes without explanation, photos do not match the quoted item, condition is vague, payment is pressured, or warranty, returns, shipping and customs documents are not stated in writing.

Ask for current product and label photos and compare the model, suffix, serial or revision details where applicable. Review seals, terminals, housing, accessories and packaging for consistency. The agreed condition and any inspection scope should also appear in the written quotation.

Confirm the exact item, quantity, condition, quoted price, warranty scope, return authorization process, shipping method, customs documentation responsibility and payment beneficiary. The quotation, photos and later shipment documents should remain consistent.