Size: +1.75 Stick On Lenses For Bifocal Optx Lens Snorkel Scu Diving Mask Snorkelling Dive Take Stick On lenses on your next dive trip for a whole experience. Just add water and adhere to the inside of your diving mask. Simple as can be! The Stick on lens turns any Glasses, sunglasses or masks into powerful bifocal magnifying glasses with unmatched clarity. If you have any question, you can message to us.