3mm fleece lined neoprene with abrasion-resistant bi-directional facing. 400 gm. Thinsulate Insulation. 800 gm. Thinsulate Ultra Insulation which creates a warm layer of insulation without adding bulk to match the boot to the specific temperatures it will be put to the test in. 100% waterproof Alpha construction. Warm and comfortable at temps from -60°F to -120°F. Aggressive outsole for traction in mud and snow. Weight: 4. 4 lbs. 7. 50 shaft height. 13. 75 circumference. Product measurements were taken using size 11. Please note that measurements may vary by size.