Totobobo mask comes in two sizes, Large and Medium/small.
Large size is suitable for most man.
Medium/small is the same mask and is suitable for most women out of the pack. To obtain smaller sizes, you can trim the edge of the mask away.
You can use the Size chart for a quick check:
If you need more accurate size estimation, please download and
print this template
to make a simple paper dummy mask. That allows you to check and compare the two sizes physically.