The Ultra Cell Knee Protection System is without question the most technologically-advanced Knee Protection System available. Several patented revolutionary design concepts come together in unison to create this System. The A.R.C. Cuffs ability to be totally adjustable for fit, yet remain rigid, along with a superior fastening design in partnership with Boa Technologies, a natural free-motion, rolling-gliding hinge, tibial plateau-capturing frame design, brace-to-boot tether attachment, and a full time-full coverage patella cup, sets this knee brace decades ahead of all the rest. A.C.M. FRAME: Anatomically correct design. Carbon fiber epoxy Matrix. Rigid and lightweight, impact distributing structure. Materials: Carbon Fiber epoxy Matrix. Weight: 1.6 pounds. ASYMMETRIC-GLIDE HINGE: Tracks the natural "rolling-gliding" motion of the knee joint. Asymmetrical design allows each hinge to set properly. Allows for automatic tibia alignment of lower frame. Adjustable external regulator from 0 to 30 degrees. Condyle shims for fine tuning fit. A.R.C. CUFF: Adjustable Retention Control. Multiform rigid lateral support. Built in Anti-Rotation connection. Stainless steel retention strips. Inverted adjustment increases lateral rigidity. Thermo-Formed EV50 shock absorbent foam padding. ANTI-ROTATION TETHER: Links the brace to the boot, making them as one. Transfers forces of a lower leg rotation. Adjustable to suit each individual. DUAL-INDEPENDENT SECUREMENT SYSTEM: Medial Macro-Adjustment. Superior security to strapping. Boa closure system provides smooth even closure and no pressure points. Quick release tabs. TELE-TRI PATELLA CUP: Telescoping Three piece design. Easily removable. High-impact Nylon 6 material. Full range of motion coverage of the knee cap. Thermo-Formed EV50 shock absorbent foam padding. WATER RESISTANT: Non-corrosive metals. Non-corrosive composites. Hand washable soft materials. UNDERSLEEVES (Included with Braces): Conically tapered cut to match the legs natural contour. Ventilated mesh promotes air flow; reduces heat build up by wicking moisture away from skin. Flat stitched quad seam for a smooth, durable finish. Durable fold-over elastic band. The braces come with an Allen wrench for making these adjustments. Note: Sold as a pair.