Tried turning it around and look underneath? Should have at least a manufacturer stamp. From that you could take a look at the currently produces and not longer produced products, and see which coils would fit. Or we can continue playing "what tank is that" lol. I saw that one somewhere on clearance, trying to remember where so.. Another method, walk in your local vape/smoke store and have them look at it, they mostly just run a fitting with xyz brand if they don't know and whatever fits get sold.