Alvra II Low GTX® Men. A sustainable and extremely comfortable mid shoe. Made from high-quality, sustainably produced Mastrotto split leather. A Vibram sole made from at least 30% recycled rubber provides an optimal grip. The footbed is made from recyclable cork. The Alvra II Low GTX® Men is a unique example of how environmentally friendly materials can be combined. Gore-Tex® lining, which combats moisture penetration, rounds of this classic mid shoe.