The McDavid #428 Pro Stabilizer is a professional quality bilateral hinged knee brace that features geared polycentric hinges with hyperextension stops, a padded hinge cover and condyle pads. Aircraft grade aluminum hinge and uprights lend rigidity, support and durability. The #428 also features a professional quality 4 way stretch neoprene sleeve with reinforced nylon pockets to house the hinge. The Pro Stabilizer offers a maximum level of knee support and protection. The thermal neoprene sleeve provides compression and therapeutic warmth to help relieve pain and promote healing. The hinges increased mechanical stability. Caution Do not apply over open wounds or if you have a susceptibility to dermatitis.