The 2013 Viper Surge ID boots are a stiff (130 flex) powerhouse of a boot that is designed to be skied aggressively. The Surge comes with the Intuition ID tongue liner (some say is better than the wrap style) which is really what makes this boot so awesome. They are 100mm in the forefoot which allows for a little extra room compared to 98mm lasts. We reccomend this boot for advanced to expert skiers who want an extremely precise fit with a stiff flex for skiing at the highest of speeds. For more information on how your ski boots should fit click here