- The Professional's Choice Combo Knee Boots provide the addition of knee protection to their 2XCool Sports Medicine Boot. They have been designed around cooling, comfort, and durability. This neoprene-free boot is constructed with ultra lightweight materials with superior breathability, and provide the support and 4-way stretch benefits Professional's Choice boots are known for.The liner of the boot is made with 2XCool performance fabric by brrr, a technologically advanced textile that combines natural cooling minerals, active wicking, and rapid drying to create a "Triple Chill Effect" that instantly and continuosly draws away heat and moisture. A new stretch Kevlar patch on the suspensory strap flexes with every step to provide ultimate support and durability without restricting freedom of movement.