The Viper 10 is were designed for aggressive skiers who take on any terrain that is put in front of them. They are a 100 flex boot which is on the stiffer side of things, have a 100mm last which is more relaxed than most of Dalbello's high performing boots and will provide you with a precise fit that will enhance your turning with great response and power. We recommend this boot to anyone from advanced intermediates to expert skiers that want some performance value, without the foot pain. For more information on how your ski boot should fit click here