The Hurley Phantom Free Men's Sandal features a Nike Free outsole and ergonomic footbed that mimics your foot's natural movement for maximum comfort and all-day wear. ULTIMATE FLEXIBILITY Hexagonal grooves are hot-knife cut into the outsole, wrapping the sidewall to enable more natural motion. Secondary hexagonal and horizontal cuts intersect the flex grooves for even greater flexibility. NATURAL STRIDE The heel and footbed mimic the shape of the foot, rolling with the ground to promote natural foot movement.