MASK NOT INCLUDED! This fog wiper is a manual device that allows the user to slide a wiper/magnet on the outside of the lens, causing an inside wiper/magnet to move in unison and wipe off fog. SIMPLE! Note that the unit price (quantity=1) is for a single pair of wipers/magnets, as used on single-lens masks; for a split-lens mask, 2 pairs (quantity=2) are required. Wide-i fog wipers for swimming goggles, scuba diving and snorkel masks, professional Diving Helmet, and Firefighter masks are also available at Amazon.