Step one: describe the need precisely
Name the product line and the type within it, the quantity you have in mind, and the market you sell into. For humidifiers, name the line — household or air — because the two are separate and neither covers the other. Name the use: the space, the scene, the task, or the installation, depending on the line. An inquiry that names the type and the use will receive a specific reply; an inquiry that names only a product word will receive a general reply.
Include the four confirmations as questions, not as assumptions: the minimum order quantity for your order, the lead time with its meaning, the specification for the exact type, and the certificates that apply to your market, by name, with documents attached. Questions asked in the first inquiry are terms; questions asked after payment are requests.
Step two: judge the reply by its documents
Judge the reply by whether it answers the four confirmations, and whether the certificates arrive as documents, not just as names. A reply that answers all four, with documents attached, is a reply the order can proceed on. A reply that answers none of them, or that answers with general assurances, is a reply that needs follow-up questions before any payment.
Compare the specification in the reply against the type you named. If the specification describes a different type, say so, and ask for the right one. If the quantity terms or the lead time do not fit your order, say so, and ask what would fit. The inquiry is a negotiation, not a formality, and its purpose is to reach terms that both sides understand.
Step three: confirm, then pay
Confirm the terms in writing: the type, the quantity, the lead time, the specification, and the certificates, all in one document or one confirmed reply. Then pay, and keep the paperwork — the inquiry, the reply, the specification, and the certificates — for the whole life of the product. When a later batch differs from the first, the paperwork is what proves what was agreed.
Do not pay on a general assurance, a verbal promise, or a reply that leaves any of the four confirmations unanswered. Payment before confirmation turns a question into a dispute, and a dispute after payment is harder to resolve than a question before it.
Before payment, confirm the minimum order quantity and lead time for your order. Certificates are available upon request.