Winter Extreme This last features our largest tallest toe-box for ultimate insulation in extreme winter conditions. The Winter Extreme last allows the foot to maintain proper circulation even when thicker socks are worn. What' unique about our last is the cycling specific heel, instep and arch shape that still maintain proper conforming fit to keep your foot securely in place while riding or walking without the need to over tighten. Our Winter Extreme last continues to forge ahead to comfort and warmth for winter cycling footwear. OUTSOLE Sub Zero rated rubber, Ice grip inserts. Wide platform rubber sole designed specifically for slippery conditions UPPER Double the insulation 400g 3M Thinsulate and built on a cycling specific winter last, Pittards WR100 Helcor abrasion resistant leather, waterproof membrane CLOSURE Tongue mounted plus additional side mounted IP1 Boa lacing system largest tallest toe-box ultimate insulation in extreme winter conditions Double the insulation 400g 3M Thinsulate Sub Zero rated rubber, Ice grip inserts. Tongue mounted plus additional side mounted IP1 Boa