I'm gearing up to place another order and was looking at the RY4 but then noticed there is also RY1, 2 and 3 also. Frankly, what I'm looking for is the closest e-liquid to the 16mg titan eliquid that came with my very first e-cig from TW. I had heard RY4 was close but then seen the 1, 2 and3 offered on Cignot and wondered what the differences were. Could anyone explain?