Removable and replaceable comfort system insole is made of sheepskin, latex and foam for ultra comfort with a Mylar sockliner for warmth. Molded rubber lug cup sole for strength and durability on rugged surfaces. Approximate boot shaft height (cuff down): 12"; Approximate mid-calf circumference: 13" ; Twin-faced grade A sheepskin with suede toe and heel guards ; Removable and replaceable comfort system insole is made of sheepskin, latex and foam for "ultra" comfort with a Mylar sock liner for warmth; Molded rubber with EVA inserts providing extra heel and forefoot cushioning;