Btw, this thing can be handy if you use 20mm or 14mm pancakes. You couldn't pull focus repeatedly (because of Panasonic implementation). But could use manual focus on the rig (slow pull why looking in EVF works).
Ask the seller about this (it is too new to get detailed user reports). jinfinance is very good known among guys who buys Chinese camera related things.
Btw, just talked with one guy who know this market well. He tells that cost if it will be produced by UK manufacturer (and in UK!) for such focus could be about $600. Weird.
DFocus is good, but it is between DIY and real product. This one is produced using high volume methods. Plus reversible gear make very big difference (at least for me).
Thanks for the tip - looks very good for the price! Would be nice if somebody could compare it against the dfocus 3 in real life. I'm quite happy with my dfocus, but this one seemes to be equally good..