Some questions will quickly reveal whether you're dealing with a professional or someone who's just moving product:

• "Can you send me a spec sheet with exact dimensions, battery capacity, and puff count?" If they can't, they're guessing.
• "What's your batch traceability process?" If they don't know what that is, they're not a serious supplier.
• "Can you provide a sample for me to test before I order?" A real supplier will send samples. A fly-by-night won't.
• "What's your refund policy for defective units?" If they say 'no refunds', that's a sign they don't expect quality.
• "Do you have any certifications or lab reports?" They might not have lab reports for every batch, but they should at least have some.

If they hesitate on any of these, treat it as a warning.