Synchwire construction is a stitchless upper thats vented and reinforced to create a lightweight cycling shoe with incredible airflow and structural integrity Synchwire is an advanced composite of thermobonded film that provides overall durability a nonwoven internal sheet for distributing the force from the closure system to the upper for direct power transfer and monofilament mesh for ventilation The BOAreg L6 Fit System provides fast microadjustability with the turn of the dial The combination of the dial lace and guides reduces weight and provides finer adjustment 1mm increments compared to traditional buckles and it offers an instant release function too The BOA Fit System dials and laces are guaranteed for the lifetime of the product Our proprietary advanced carbon composite outsole plate ensures efficient power transfer and responsive feel at the pedals while allowing 5mm of adjustment for optimal cleat positioning Its the ideal balance of stiffness and durability with light weight Reflective details enhance visibility at nighttime or in lowlight conditions when illuminated by a light source such as headlights by returning the light back to the source and reaching the drivers eye