The PU lite midsole is resilient and supportive for long treks and voyages into the deep wilderness. These Italian made boots have excellent traction and cushion and proper moisture management. Great for traditional hikers looking for heavier duty boots that will last for years of hiking. Durable full grain greased Idro-Perwanger® leather upper repels water and offers superior support. Soft calf skin leather lining is extremely comfortable and supple. PU Lite midsole absorbs shock and protects feet for long lasting comfort. Vibram® Sasslong outsole with Impact Brake System™ for excellent traction and impact force reduction. Ideal Terrain: Heavy duty backpacking and hiking in technical terrain. Last: TrekIdro-Perwanger Leather (2.6-3.2+ mm) This premium silicone impregnated rough-out leather is made for us by Perwanger Leather of Italy. Perwanger has been making leather in the Southern Tyrol region of Italy since 1780 and tans their Idro-Perwanger hides with a special process to make them extremely water repellent while still remaining breathable. This leather is the most durable available and is made from the corium, the strongest part of the leather.Impact Brake System (I.B.S.) A proprietary technology in outsole design where the lugs of the soles are oriented in opposing slanted directions. This opposition increases braking power by an average of 20% and decreases impact forces by and average of 20%.Trangoflex A lightweight synthetic insole stiffener that provides an exceptionally smooth flex pattern and the ideal stiffness for semi-automatic crampons.