Recommended for surgically treated knee joints, perfect for post treatment for strain, sprain & fracture dislocation. - Knee immobilizer 19 inches Sizes Inches CM Small 14.8-17.2 37-43 Medium 17.2-19.6 43-49 Large 19.6-22 49-55 XL 22-24.4 55-61 XXL 24.4-26.8 61-67