USED Mammut Ducan Low GTX Shoes - Mens Sapphire Dark Sapphire 12 US 11 UK. A literal spring in your step Mammut Flextrontechnology uses a spring-steel sole to provide effective shock absorption energy transfer and stability to keep your energy up and support your natural stride. A Vibram outersole provides reliable grip and a trusted GORE-TEX membrane keeps you protected from adverse weather. All this in an anatomically tailored design for a comfortable precise fit. The Ducan collection a classic for a reason. Specifications for Mammut Ducan Low GTX Shoes - Men's: Manufacturer: Mammut Men's Shoe Size: 11 UK 12 US Gender: Male Age Group: Adults Heel Height: 10 mm Footwear Type: Shoes Activity: Hiking Weight: 420 g Footwear Closure: Laces Fabric/Material: Double Layer Engineered Mesh Footwear Upper Fabric/Material: Double Layer Engineered Mesh Insole Material: Vibram Flextron Lining Material: Core-Tex Features of Mammut Ducan Low GTX Shoes - Men's Elasticated tongue construction Package Contents: Mammut Ducan Low GTX Shoes - Men's Mammut 3030-03521-50293-1110: Ducan Low GTX Shoes - Men's Sapphire Dark Sapphire 11