Dust-Off is a brand of dust cleaner (refrigerant-based propellant cleaner, which is not compressed air

Compressed air

Compressed air is air which is kept under a certain pressure, usually greater than that of the atmosphere. In Europe, 10 percent of all electricity used by industry is used to produce compressed air, amounting to 80 terawatt hours consumption per year....

 and incorrectly called "canned air") containing difluoroethane; it is used to remove particulates and dust from computers and electronic equipment. Dust-Off products are used to remove dust, debris, fingerprints, and smudges from hard to reach areas of keyboards, screens, and other components of electronic equipment.