I got one that looks exactly like the one in your pic. Cost US$10.
It works fairly well for me. One thing I noticed is that the "smart" battery function of the DJI batteries is pretty confused by this bar if the batteries are at different charge levels. I had posted elsewhere about this, but I'll repeat.
I only have 2 batteries. If one battery is at 20%, and the other is at 60%, and I plug both batteries to the bar, only one will continue to charge and the "smart" circuitry will shut off the other battery. If I power up the "off" battery (just like powering up the Phantom: 1 brief press followed by a 2 second press), the first battery will turn itself off. Powering up the first battery will cause the second battery to turn off. This is very repeatable.
What I do: I plug the lesser charged battery into the bar and let it charge up to the same number of flashing LEDs that the higher charged battery displays when I do a power check. Then I add the higher charged battery to the bar. Then both batteries will charge simultaneously. Apparently the batteries don't need to be exactly at the same level, but they need to be reasonably close. Otherwise, the charge circuitry in one of the the batteries will shut down.
Even if the batteries have a similar charge level, I still might have to do the power-up button press on one of the batteries to get it going. Once I do that, everybody seems happy. If I think of it next time, I'll get out the stopwatch and see if charging 2 batts simultaneously is actually quicker than charging them sequentially without using the bar.