Salewa Men's Pro Guide Performance Fit Hiking Boot 100% vibram Imported Vibram sole Shaft measures approximately 8.5" from arch Heel measures approximately 1.25" Boot opening measures approximately 11" around Multiple lasts means differentiated fit only when the foot has the space necessary is it possible to eliminate foot rubbing no rubbing no blisters 3F power unbeatable combination of flexibility ankle support and precision in fit improved with a steel wire for additional heel containment anatomically positioned Salewa flex system Vibram salewa PRO outsole GORE-TEX insulated comfort Duratherm XL lining