Scuba Choice Blue Diving Dive Snorkel Mask Nearsighted Prescription RX Optical Corrective Lenses Available corrective lenses: -1.5, -2.0, -2.5, -3.0, -3.5, -4.0, -4.5, -5.0, -5.5, -6.0 Tempered glass lenses Crystal silicone facial skirt and mask strap. Unique buckle design which allows you to adjust the mask easily