Tingley profile knee boot is formulated with high quality PVC resins and low temperature additives. The result is a boot that has good abrasion resistance and excellent flexibility in cold temperatures. Injection molded seamless construction provides 100 percent waterproof protection. Composite safety-toe meets ASTM F2413 m I/75 C/75 and does not transfer cold or set off metal Detectors. Calf Relief expansion (scratches) expands up to 1.5 inches for more calf comfort. Flexible upper material stays supple in cold temperatures to make walking easier. Outsole material is soft for excellent slip resistance and absorbs shock when walking. Cleated Outsole spits out debris for excellent gripping action. Removable polyurethane, contour insole features three layers to wick perspiration, promote faster drying and absorb shock for all day comfort.