Mueller HG80 Knee Stabilizer Synthetic The Mueller HG80 Knee Stabilizer offers comfortable an lightweight protection to help stabilize and provide support for stiff, weak, and unstable or sore knees. With MUELLER`s exclusive HYDRACINN fabric, the HG80 Knee Stabilizer offers superior support with heat management... Size - (See Description) | Color - (See Description) Authorized Mueller Dealer. All racquets are strung and ready for the courts! SEE SELLER DETAILS FOR RETURN POLICY.