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 the fog. SIMPLE! Note that quantity=1 is for a single pair of wipers/magnets, as used on single-lens masks, and for split-lens, 2 pairs (quantity=2) are required. This product is optimal for double-pane lens masks such as ski/snowboard mask. Wide-i fog wipers for swimming goggles, scuba diving, and snorkel masks, airsoft/paintball masks, motorcycle visors, professional dive masks, and Firefighter masks are also available at Amazon.