Dual density Nitrile Rubber/PU sole construction Removable extra thick PU insock Fuel and Oil resistant, Non-marking sole SRC slip resistant and anti-static sole Flex zone technology Composite toe cap and TPU toe cover Out sole heat resist to 300 degrees Celsius 3M Thinsulate 400g thermal insulation Meets AS 2210.3:2019 certified by BSI BMP 622279 Jb's Arctic Freezer Boot