OCEAN REEF - Optical Lens Support 2.0: This frame is engineered with removable, snap in, legs. The frame can be installed in all OCEAN REEF FFSM and scuba masks (with the exception of XS size). This frame is a removable and customizable corrective lens option that no other FFSM offers. Convenient optical correction that transforms in an inexpensive pair of glasses, when you&&';;re done snorkeling and scuba diving. 2 YEARS WARRANTY And, It&&';;s environmentally friendly! OPTICAL LENS SUPPORT Set includes Frame, 2 removable legs - made from non-plastic, plant-derived material.Comes with organi cotton bag and neoprene floating strap to not loase the glasses once on board.A small step to reduce plastic use in the world! Compatible with all OCEAN REEF FFSM, except size XS, Compatible with all Scuba IDMs! NOTE: Does not come with lens. Lens can be purchased here RX022 or purchased from an optician if you take the frame to get the lens fitted to the lens of your choice.