How to choose the right EPOC Flex Capsize?

The Flex cap sizes are equivalent to centimeter head circumference, measured along the line, where a hat would sit. The caps come in steps of 2cm head circumference, even numbers. If the size actually measured is an odd number choose the next-larger cap.  E.g. choose size 54 for all circumferences from 52,5,0 thru 56,4 centimeter, etc.

In an example of a person with long/thick hair, when measuring the head circumference you measure over the hair, so it is already accounted for. So again, with a measured circumference of 53 cm (including hair) I’d first choose cap size 54. Only if I then encounter a bad fit, e.g. Pz hovering in thin air, as a second choice I try the next larger size, 56, because it will slip further down the head.

You can refer to this link for how to select the most suitable capsize  https://emotiv.gitbook.io/epoc-flex-user-manual/cap/choosing-cap-size