The UGG Ultra Tall woman's boot is made with twin-faced sheepskin that wicks moisture away from your feet. The lugged outsole and removable/replaceable insole is great for both comfort and function. The heritage UGG Australia Tasman woven tape on the back of the boot adds a little something special to this tall boot. 1.Approximate boot shaft height: 12" 2.Approximate mid-calf circumference: 12" 3.Twin-faced grade A sheepskin with suede toe and heel guards 4.Removable and replaceable comfort system insole is made of sheepskin, latex and foam for "ultra" comfort with a Mylar sockliner for warmth. 5.Molded rubber lug cup sole for strength and durability on rugged surfaces