ELLIE 121 JACK Mens boots Leather Heel measures approximately 1 inches" Small = 8-9, Medium = 10-11 and Large = 12-13. Man Made Material Circumference at ankle is about 10" Circumference at mid to upper calf is about 18" - 19" Full-length zipper is sturdy and works perfectly, Zipper runs on the inside of the leg make them easy to put on and take off