How much espresso will my NEO Flex yield?

How large will my shot be? If I want a smaller or larger yield, how can I achieve that?

The NEO Flex will yield a shot up to 45ml, depending on the dose being used/how much water is absorbed by your coffee bed. 

If you wish to have a smaller shot, simply brew with your cup placed on a coffee scale, and terminate the extraction once your desired yield is reached: Terminate your extraction by holding the lever steady in place while you swap your cup, then continue to lower the lever to expel the remaining brew water and dispose of this excess.

It is important to finish the pull, rather than just let go of the lever once you've reached your desired yield, to prevent a rebound affect from the pressure built up inside the brew head. 

If you wish to have a larger output on your NEO Flex, we'd recommend picking up an additional portafilter or Second Shot Plus (complete second brew head) so that you can prep two coffee beds at once, and easily swap between pulls for back-to-back brewing.