Undeniable Open Knee Sleeve Protective By Under Armour Small/Medium (Cir 12-15in) Made and designed by Under Armour. Heat Gear Lining Keeps the Moisture away and Their is an easy to use UA Strap. Open patella (kneecap) relieves pressure so you can stay focused. Provides compression, thermal comfort and muscle support that will keep you playing longer, harder. HeatGear-lined perforated neoprene wicks sweat away, keeping your knee cool and dry for max comfort