Ocean Reef Optical Lens Support 2.0This frame is engineered with removable, snap in, legs. The frame can be installed in all Ocean Reef scuba masks (with the exception of XS size and ARIA Junior). This frame is a removable and customizable corrective lens option that no other full face snorkelling mask offers. Convenient optical correction that transforms in an inexpensive pair of glasses, when youre done snorkelling and scuba diving. Left and Right optical lenses are also required.