Features of the La Sportiva Women's Spire GTX Boot Low-cut and lightweight synthetic hiking boot Breathable Gore-Tex-Surround Technology Upper: Abrasion resistant mesh/ Nano Cell 2.0/ PU TechLite Toe and Heel Lining: Gore-Tex- Surround Midsole: 5mm Ortholite Insole/ Compression Molded EVA/ STB Control TPU Inserts and Nylon Mesh/ Gore-Tex - Surround Aeration Channels Sole: Vibram Nano XS Trek Compound with Impact Brake System Enhanced braking effect Enhanced traction Enhanced shock absorption Reduced articultaion fatigue Vibram is the world leader in High Performance rubber soles