Re-designed with a fit inspired by our S-Works model this shoe offers performance-enhancing Body Geometry technology Boa dial adjustment & our glass composite sole for a great blend of performance & value. FACT carbon/glass fiber reinforced outsole is directionally rigid for outstanding power transfer: 8.5 stiffness index Performance-enhancing BG features in the outsole & footbed New Lightweight Boa L4 rotary closure & forefoot Velcro strap for on-the-fly tunability & dynamic fit; features a quick-release lace pull Synthetic upper with mesh venting for supple fit Ultra-vented tongue for breathability 3-bolt cleat pattern fits Shimano SPD-SL Look Time & Speedplay Approximate weight: 270g (1/2 pair 42)