The Viking MET Guard boot is your mining boot. Sbr blended nr upper with a polyester lining. It has abrasion, and slip resistant 100% natural rubber lug soles. The MET boot has a highly chemical resistant rubber upper and achilles tendon and ankle protection. Snug Fit design boots: Slip-on boots that feel like they are laced on; superior ankle/heel support to reduce incidences of ankle roll-over; superior arch support to reduce fatigue, finally a gum boot that moves with you, as part of you. Shaft measures approximately 14.25" from arch, Boot opening measures approximately 16" around. CSA M Metatarsal Protection, CSA Z195-14 / ASTM F2413-11 Grade 1 Steel toe and plate. Viking boots are different from other boots because we focus on safety, not as a guide - but as a philosophy, making sure every boot we produce exceeds the standards and embraces comfort and wellness for the wearer. We work with miners, foresters, fishermen and firemen to understand their comfort issues and bring their responses to market in our boots.