You may not be aware that there are several versions of the FoamasterII. The difference is the amount of, or lack of, adjustability of the concentration of shampoo. I just bought a gun myself and the night I got it I started playing with it. Mine would only show zero or 'A' with 'A' being 4 oz shampoo to 1 gallon of water. I had read everywhere about the adjustability of the gun and couldn't figure out why my dial wouldn't turn any more. I could even see the other settings on the dial. As it ends up I believe there are 3 different versions of each container sized gun, one offers no adjustment at all, it foams all the time. The second if the gun I got and the other is the fully adjustable version. Check the model numbers and you'll see the differences.