I'm not exactly sure what the mod setting is, but I think it's the ratio of the number of teeth to the diameter of the wheel.

I know that generally mod 1.0 means for a 60mm wheel, you get 60 teeth; for a 120mm wheel, it's 120 teeth.

So, mod 1.0 would have 3.14mm pitch (circumference = pi*dia, dia = 60, so 188.49 circumference. Divide by 60 gives pi).

If it's 11mm, then it's probably 10.995, or mod 3.5 (3.5*pi = 10.995).