As far as I know all bottle types have the same size teat but different flows. I'm not familiar with Mam but looking on their web site the system seems the same as the bottle types I am familiar with.
They do a newborn teat which is the slow flow (o+ months and no1), a medium flow (2+ months, no2), fast flow (4+ months, no 3) and 6+months which is an x cut teat. The width, the length and the shape of the teats will be the same for all of them. They don't do different size teats with different flows.
Do you have something different?
Laura