the seller has their own line of batteries and lights, think they also sell the AAA Glaree which is pretty good. A few months back I had gotten one of their 1000 lumens E series light or something, but the side switch wouldnt budge and was impossible to switch modes so I returned it. they also have their own charger which I think is a clone/rebrand of ultrafire digital display one, it’s a pretty good charger, got a crazy deal on it, as to the nitecore being a fake, who knows, there are a lot of fake d4’s out there, but the seller seems legit.