Blundstone Men's Work Series 179 100% Leather Imported Synthetic sole Shaft measures approximately 5.5" from arch Heel measures approximately 1.5" Boot opening measures approximately 9.5" around Polyurethane (pu) midsole thermo urethane (tpu) outsole highly resistant to hydrolysis and microbial attack - oil, acid and organic fat resistant. Outsole heat resistant to 284 degree Broad fitting 200 joule impact resistant steel toe cap Xtreme comfort eva footbed with poron xrd heel and forepart inserts providing great underfoot comfort Steel shank-ensures correct step flex point, assists with torsional stability Ergonomically engineered toe spring for reduced wearer fatigue and full heel breast with arch support for ladder and gantry safety