From Vionic, the Gretchen Knee High Leather Boots feature: Premium leather upper Zipper closure  Back gore panel provides a tailored fit Synthetic lining Built in VIO MOTION Technology featuring contoured arch support, with shock-absorbing cushioning, and a deep heel cup to provide stability, and forefoot flexibility Durable synthetic outsole Approx. 15" boot shaft height Approx. 14.4" standard boot shaft circumference Approx. 16.5"  wide boot shaft circumference   Approx. 1.13" platform height Approx. 1.75" heel height Imported. It is recommended to wear your new pair for a few hours to allow your feet to adapt to the new support.