Vantelin Kowa Knee Warmer Supporter Size: Large L size Moisture-absorbing and heat-generating material warmly wraps the knee. Firm support with patented taping structure! For both right and left legs. ・While sitting on a chair, etc., and gently bending your knee, measure the circumference (cm) of your kneecap as shown in the illustration. ・If you fall between two sizes, we recommend the larger size. Small/S size: 31-34cm Regular/M size: 34-37cm Large/L size: 37-40cm Extra Large/LL size: 40-43cm 1 piece/box 5x20