Waterproof, warm and durable slip-on winter boot. Rated -25F/-and 32C. How to Measure-1.Fold up at dotted line.2.Place against a wall or other 90 degree surface.3.Place heel against fold/wall on flat level surface.4.Mark the end of the longest toe with a pen or pencil.5.Measure both feet and use the larger measurement.6.Read measurement and compare to size chart.7.When comparing on the size chart, determine the closest larger measurement and use that number to determine your shoe size for your country’s shoe measurement standard.