Ligament Protection Redefined. The Breg LPR Knee Brace is one of the lightest functional knee braces on the market. The LPR is now available in an OTS (off the shelf) version with the fit and feel of a custom brace. Aerospace materials and breathable AirTech padding makes this brace extremely rigid, amazingly light, and very comfortable to wear. The LPR knee brace offers the utmost in ligamentous support and protection.