Most of the websites I can find state that KelTec makes 7 versions of the SU16...but none of those are designated SU16F or SU16FA. Are those specific Canadian models? At least one retailer lists the SU16A...but ships out a rifle that is marked SU16F on the receiver, in a box labelled SU16FA! Confusing-er and confusing-er. The box, as stated above by Rifle Master, indicates that a 5-round mag is included...but the retailer websites say no mag. They're upfront about it, not trying to hide anything, so that doesn't bother me.
I surprised myself by picking up one of these recently for a good price, after reading and hearing for the past few years that newer production guns seem to be pretty problem-free. No certificate from Vault or anyone else, and in fact no hard-copy receipt at all. Waiting to hear from the retailer regarding the model designations and the warranty/receipt/certificate issue.
Right off the bat I was disappointed to find that the onboard magazine storage in the buttstock apparently only works with original KelTec magazines. The Magpul and MFT magazines I already have don't fit or latch into that opening at all; instead of being a useful and distinctive feature, that big ugly hole is...just a big ugly hole...
I've owned an RFB and a couple of RDB's, and they all impressed me with their innovative designs and also by having a much-higher-quality "feel" than I expected. Sadly, their odd ejection patterns, which along with the bullpup configuration were what attracted me in the first place, eventually prompted me to move them down the road. Inspection and access to the chamber was too much of a PITA for my taste.
The SU16 is kinda the opposite; the chamber is as easily accessed as that on a "real" rifle

...but the feel of quality? Lol...not so much...