Mine came assembled like on the picture, but the polarity was reversed!
I am using this with a IC5 LiPlus Intelligent Digital Balance Charger to charge a Thunder Power ProLite V2 with 730mAh. When I first connected it, the charger gave the following error:

BATTERY VOL ERR
CELL LOW VOL

I measured the output and figured out that the battery connector on the board needs to be reversed for this to work correctly in my setup! Pulling of the white plastic casing of the 2S connector on the TP/FP Adaptor, rotating it 180 degrees and putting it back on did the trick (no soldering is required, the pins stay on the board, simply lift it off with a knife or similar). Now it charges as it should.

From how I understand this, I'd figure that is the same for the 3, 4 and 5s connectors, but I have no such cells at hand to test this.

--> if your charger shows you the above error, and your adapter is assembled like on the picture (press button on battery connector towards cable that goes from adaptor to charger), try reversing the plastic casing of the battery connector.
I give this product 2 stars. Review by Ledin, Banz