Pulsar™ PVC Knee Boots feature a Calf Relief Expansion (CRE) gusset that expands up to 1.5 inches for more calf comfort. 15" knee boots are formulated with a high-performance outsole and a unique PVC blended upper resulting in a boot with good abrasion and slip resistance and excellent comfort and value. The composite safety toe meets ASTM F2413 M/I/C and does not transfer cold or set off metal detectors.