Size Chart: Knee Cap With Open Aatella

Size Type Inches Cms
S 14.8 - 17.2 37 - 43 
M 17.2 - 19.6 43 - 49
L 19.6 - 22.0 49 - 55
XL 22.0 - 24.4 55 - 61
XXL 24.4 - 26.8 61 - 67
XXXL 26.8 - 29.2 67 - 73