Aqua Optics stick-in magnifier lenses allow divers and snorkelers a quick & economical solution to adding magnification in dive masks. Reading your fish ID card, watch or camera settings is now possible without the expense of a full prescription mask. These optical-quality glass stick-on lenses are removable and reusable if you change masks, yet won't accidentally wash out if your mask is flooded with water. Each package includes two semi-circular lenses, installation glue, and complete instructions. Installation takes minutes, and the glue sets completely in 6 hours. Five powers available to fit a wide range of needs. Scuba mask is NOT included. Install these lenses in any scuba or snorkel mask with flat lenses.