Chilled legs sustain injuries easily. The X-BIONIC® LEG PK-1 Energy Accumulator® offers targeted protection from the cold because your muscles lose warmth differently in different areas. When pedalling the knee bends repeatedly. Traditional leg warmers spread thin with that movement. With LEG PK-1 Energy Accumulator® the system works like an accordion with chambers and ducts that fold and unfold, allowing our ExpansionKnee™ to gain insulative attributes. At the same time, the X-BIONIC® partial compression reduces muscle vibration and supports muscles and joints. That keeps legs even on freezing days powerful and optimally temperature-regulated.