Knee Brace Undersleeve – Compression Liner for under Orthopedic Knee Supports – Non-Slip Breathable Sleeve for Skin Protection, Chafing & Rash Relief (L/XL – 21″-31″). ✅ SIZED BY THIGH CIRCUMFERENCE (6″ above mid-knee): SM/MD fits 16″-26″, L/XL fits 21″-31″.