Thanks for the review.  Is AUDBOS K3 the same as the Maogosi K3?  They look entirely the same, except for the cable and accessories package.  I would fully agree with the Maogosi K3 vs FLC8s comparison that you made.  The FLC8s are a definitive step UP from the K3, without question.  My suggestion is to save up your money and get a used set of the FLC's.  The K3's are a good headphone, but the FLC's are AWESOME.  I also like the Kinera BD002 hybrids better than I like the K3's, and they're a third of the price.

I have no idea. I reached out to Audbos to find out but haven't heard back yet. I suspect they either share the same OEM, Audbos is a North American focused division, or something of the sort. There are also Magaosi models with the same design as the DB-01/02.
 
FLC 8S is a step up from most earphones. They're something special for sure. 
 
I haven't tried the BD002, but I did give the BD005 a go and really enjoyed them. I definitely wanted to order a pair

Great review B9! I'm still waiting for my Sendiy M1221. I hope it sounds as good as your K3!

Thanks Crab! I hope so too. They have a good rep and their build quality looks excellent. They'll be a worthy buy for sure. *edit - looking at M1221 pics the cable looks to use the same jack, y-split, and connectors as the K3's second cable. Neat.*