Ultra-light carbon fibre sole provides excellent rigidity. Ideal heel positioning for maximum power output. Patented multi-vent system circulates air around your entire foot for cool, dry comfort. BOA L4 technology offers quick, on-the-fly adjustment with even pressure distribution and an ultra-light fit. Ergo Air II nylon-reinforced outsole is lightweight, stiff and efficient. Patented multi-vent system for heel-to-toe airflow. HRS-90 system maintains heel placement during the pedal stroke and maximizes power transfer. Synthetic leather and mesh upper is supple, breathable and water-resistant. BOA L4 system is ultra-light, provides quick on/off and evenly distributes pressure. Have been used exclusively indoors for spin classes. Like new condition. Paid over $200, sell for $85.