Head Edge Lyt XR R HV Ski Boots The Edge LYT XR is the ideal ski boot for advanced skiers. Hi-Top Tech provides direct contact between leg and shell. The result: you drive better with less effort. Your energy is transferred directly to the ski with optimal control. The Duo Flex is here to help. The more you press, the stiffer the flex becomes. Flex is also reactive and elastic. Her curves have never been so explosive.