TYR Arc 180 Water Sports Mask Arc 180 Swim mask is perfect for those swimmers who do not want to wear goggles or prefer a larger frame structure that does not sit inside the eye sockets Smaller lens design provides universal one-size fits all fit to adult men and women as well as youths and silicone headstrap with molded grooves ensures a secure fit Polycarbonate curved side no center post mirrored lens with single clear split silicone headstrap and slide ratchet system on side for easy adjustment Designed for masters swimmers triathletes fitness swimmers open-water swimmers and recreational swimmers