These boots feature top of the line technology:  1) Michelin MX Hybrid Sole = Provides Traction and Stability, offers tear and abrasion resistance, extreme durability 2) Double Flex Control System = Polyurethane joint in ankle area designed to improve front and rear flexibility -- up to 18 degrees forward and 15 degrees backward 3) Boot Leg Structure = comfortable fit 4) Rubber Heat-Guard = superior grip on bike 5) Calf Adjustment System 6) Fastening Band = allows ankle to flex, but prevents hyperextension 7) Quick Release / Locking Aluminum Buckles