SIZE EYE TO CHIN EAR TO NOSE
CHILD 4" or less 3.5" - 5"
SMALL/MEDIUM 4" - 5.5" 4 3/4" - 5 1/2"
MEDIUM/LARGE 4 3/4" - 6" 5" -  6"
LARGE/XLARGE 5.5" - 6 3/4" 5 1/4" - 7 1/2"