FITFLOP. O42-399. SERENE. METALLIC MIDNIGHT NAVY. Smart self-assured in control. That s what these classic slip-on mules say. Beautifully crafted in soft metallic leather with topstitch and seam details and made with our all-day-cushioning DuocomFF midsoles this is a sharp style that s easy to wear. Try them with cropped loose or skinny trousers.