Boa Fit System The SOLID GEAR Polar GTX is a one-of-a-kind safety shoe that combines premium nubuck leather with CORDURA ripstop fabric and a waterproof and breathable GORE-TEX membrane. In addition, these great boots feature a synthetic winter wool lining, BOA Fit System and an oil-resistant, slip-resistant Vibram outsole. Upper: Nubuck leather and CORDURA. Lining: Synthetic wool with a waterproof and breathable GORE-TEX membrane Outer sole: Oil- and heat-resistant non-slip rubber Midsole: High-performance EVA foam with TPU heel counter Insole: Made of EVA breathable insole with poron pads Feature: BOA Fit System Cut: Wide Sizes: 36-48 Safety Standard: EN ISO 20345:25XL S3, SRC, WR, HRO Protection: Fiberglass protective instep and soft metal-free toe contact area