Scubapro Crystal Vu MaskThe most important consideration in mask selection is fit. No two faces are alike, and the SCUBAPRO broad range takes individual differences into account. The basic difference in masks lies in the number of lenses. Single lens masks were the first developed and remain a popular choice worldwide because they provide a broad, uninterrupted view. With the advent of silicone skirts, twin lens masks have become increasingly popular because they typically