JSB BS61 Stretchable Knee Cap Support for Sports and Pain Relief is Perfectly Elasticity, Comfortable to Wear with Breathable material and Ideal Compression. This tubular knee cap support is Ideal For : Knee Joint Pain, Arthiritis, To Protect Against Cold, To Provide Compression to Knee and for Sports Use. This knee joint pain support is washable and has a long life. Washing Instructions : Wash in Cold Water and Shade Dry on Flat Surface. Do not Hang for drying. How to Choose the RIght Knee Cap Size for You : Take a Measuring Tape and measure the circumference around your knee patella ie. the centre of your knee. Small 12.4" to 14.0" (31.0 to 35.0 cm) : Medium 14.0" to 15.6" (35.0 to 39.0 cm) : Large 15.6" to 17.2" (39.0 to 43.0 cm) : X Large 17.2" to 18.8" (43.0 to 47.0 cm) .