A Pre-Submission (Pre-Sub) is the most common kind of Q-Submission: you send FDA specific questions about a planned submission and get written feedback, optionally with a meeting. It has no user fee, and it is the cheapest way to avoid a surprise at review.
Specific questions FDA can answer from your package: is this predicate appropriate, is this test plan adequate, does this clinical study design address the risk, are these proposed special controls right for a De Novo. "Will you clear my device?" isn't one; FDA won't pre-decide a submission.
A cover letter, the device description and intended use, the regulatory history, the planned submission, and for each question the background FDA needs to answer it: protocols, rationale, the data you have so far. Fewer, sharper questions get better answers.
FDA aims to send written feedback within 70 days of receipt, or at least five days before a scheduled meeting, whichever is sooner. You can ask for a meeting by teleconference or in person. Afterwards you send meeting minutes, and FDA confirms or edits them.
The same program carries Breakthrough designation requests, study risk determinations, informational meetings and submission-issue meetings after a deficiency letter.
General information, not regulatory advice. FDA decides every classification and submission; confirm your route with FDA (a Pre-Sub or a 513(g)) or a qualified regulatory professional. Fees and review goals are planning figures; check FDA's current schedule.
More: Choosing an FDA pathway · Traditional, Special or Abbreviated 510(k) · De Novo in plain terms · 513(g) requests in plain terms · The Breakthrough Devices Program