Outstandingly designed for your fastest efforts. With its ultra-sleek lines, optimal power transfer, and refined professional features, the RC903 is the pinnacle of the most advanced technologies for a performance-enhancing racing shoe that feels and functions differently from anything you've worn before. The S-Phyre RC903 is a high-performance road cycling shoe compatible with SPD-SL cleats. Precise fit: Two low-profile BOA Li2 dials allow for quick and precise micro-adjustments. Optimal stiffness: reduces energy loss and maximizes power transfer. Anti-twist heel cap: stabilizes the heel and helps manage the strong twisting forces that occur during explosive acceleration. Breathable shoe: Lightweight microfiber leather upper with perforated ventilation openings keeps your feet cool even during intense activities.