If you're looking for a comparison, the Dalbello Viper 10 Ski Boots are identical to the Viper Surge in fit and performance features, just a bit softer. An ideal choice for budget-minded intermediate and advanced skiers looking to step their game up and rip harder this winter, the Viper 10 is rocking a flex index of 100 which puts it right in the middle of the new Viper series - not too stiff and not too soft. Along with a transparent polyurethane shell, there's a TruFit Performer inner boot that can be worn right out of the box or custom thermo fit at your ski shop. Foot Shape: Men Flex: 100 Width: 100mm