Multiple items don't even exist.I have bought several Coil packs in the past from fasttech and when they had authentic in the description, they actually were and checked out as such.
As far as the items with fake scratch codes, don't know about all of the companies but at least 2 have a system that that doesn't work in. Those clones with fake scratch codes have the scratch code they took off of a legitimate item and the serial off that item. Now this doesn't work with at least eleaf items or Nitecore items as when you enter the scratch code both will tell you how many times it has been checked before. Probably a lot of the other manufacturers do as well. If you are not the first to check it...The item is fake. They maybe using the codes and serial numbers off of a few legit one to make the fakes but in general every fake I have seen has the same serial number.
The example I will give here is a vape shop purchase of an Istick 30w locally. It had the scratch code and serial number. I checked it on Eleaf and it had already been checked over 4,000 times. I took it back to the vape shop immediately and told him it was fake per Eleaf and he needed to refund it. I showed him a print out from the check. He refunded it. I went elsewhere and bought another. When I checked it, it was legit and said congratulations you are the first to check the code.
I got a Nitecore charger off of eBay and it checked out as fake. Nitecore site said it had been checked multiple times and was not genuine (Yeah I know eBay). This was a US seller with only one negative out several thousand feedbacks. I asked him to refund it, he refused and claimed it was genuine. I disputed it with paypal and got the money back a month later. In the meantime I bought another nitecore charger locally and it checked out as genuine. The Nitecore system responded with congratulations your product is genuine and you are eligible for warrantee coverage.
I haven't bought any real hardware from fasttech but I don't think they sell fake stuff when it says authentic in the item name. I have purchased Kanger coil, Seals and glass replacements from them. They were listed as Authentic, they checked on Kanger site as such and each package had a unique serial number.
$56.80 Authentic Snow Wolf Mini 90W TC VW APV Box Mod - 5-90W / 212-662'F (100-350'C) / 1*18650 at FastTech - Worldwide Free Shipping