Bogs Women's Classic Ultra Hi Boot 100% Fabric Imported 100% waterproof, warm, and comfortable Upper made from hand-lasted natural rubber laid over a 4-way stretch SBR/CR bootie Internal midwedge with 7mm of rubber sponge cushioning. Gain almost 3/4 inch of insulating cushion with 7mm of the bootie and the 5-7mm insole Aegis antimicrobial contoured insole Comfort rated from +50 to -40 degrees