I need some pinion gears for my MMM/ Castle-Neu setup. So far, I know that I'll need a 5mm diameter pinion with 32Pitch. But what's with all these .8, 1.0 mod? people are talking about?

On Robinsonracing website it shows both .8 and 1.0 module pinions. What are the difference? and are they both 32pitch?

Thanks!