When it comes to the cleanliness of their telescope's optics, Astronomers can be justifiably meticulous. Since dust is all around us, it is almost impossible to keep it from accumulating on a telescope's optics entirely. However, at least when you're between observing runs, you don't have to allow your optics to take on dust. AstroZap dust covers are proudly manufactured in the USA and are made from a material consisting of a mixture of nylon and cotton with an elastic strap to provide a tight fit over the Truss-Tube RC Dobsonian's open end. The primary and secondary mirrors are thus shielded from dust collection, leading to sharper images.