DEMO Zamberlan Ull GTX RR WL PL Boa Hiking Shoes - Men's PFAS-Free Black/Grey 12. Gore-Tex Insulated Comfort membranes combined with Primaloft insulation provide two layers of extreme warmth and comfort while the Vibram Star Trek II outsoles provide exceptional grip on snowy icy terrain. The patented double BOA closure system allows for customizable fit zones ensuring a more comfortable personalized fit without ever having to take off your gloves.image Specifications for Zamberlan Ull GTX Boa Wl Pl Boots - Men's: Manufacturer: Zamberlan Gender: Male Color: Black/Grey Insole Material: Flex 4mm + PE Footwear Upper Fabric/Material: Synthetic Weight: 965 g Outsole Material: Zamberlan Vibram StarTrek II Midsole Material: Double Density PU Wedge + Light TPU Layer Lining Material: Gore-Tex Insulated Comfort Footwear Type: Shoes Package Contents: Zamberlan Ull GTX RR WL PL Boa Hiking Shoes - Men's PFAS-Free Zamberlan 3032ZBGM-47-12: Ull GTX RR WL PL Boa Hiking Shoes - Men's PFAS-Free Black/Grey 12