The green Grenade Rubber Dust Blower Ball from Amzer is used to clean dust and debris off lenses, LCD screens, filters, glasses, and other optical equipment that needs continual cleaning and maintenance. The grenade-shaped silicone blower has a built-in valve that only lets clean air in, so dust is not reapplied to the surface of what you are cleaning. After squeezing the elastic body of the blower, it restores itself to its original shape, and the flat bottom of the blower ensures it stays upright on a flat surface and does not roll away.