Hi-Tec Women's Altitude Ultra Light Hiking Boot 100% Leather Vibram sole Shaft measures approximately 4 1/2" from arch Boot opening measures approximately 9" around Cushioning Technology: Comfort-Tec--An insole offering superior cushioning and comfort. Outsole: Vibram--Vibram rubber outsole provides maximum traction on both wet and dry surfaces. Midsole Material: Compression-Molded EVA--The EVA material is heated, reducing the density, for a lighter weight. Model Number: 40089 Recommended Fit: These shoes run True to Size.