"The Baader Turbo Film is the highly transparent crystal clear film (not Mylar!) developed for scientific applications and used as the base material for the renowned Baader AstroSolar. It is a monomer film which was found after thoroughly testing more than 200 different film samples on Baader Zeiss autocollimator. This film was used in German Science Institutes as an optical membrane for nuclear and particle physics experiments. The basic substrate has been further refined and homogenized by a proprietary annealing process that was developed exclusively for Baader. Due to these treatments Turbo Film attains near-perfect homogeneity and performs equal to a 1/10 wave plane parallel optical window. In fact, it has the lowest wedge error of any existing optical window. Turbo Film will protect your valuable optical equipment, close telescope tubes against dust and humidity, greatly reduce air currents - all without reducing the optical quality of your telescope. This amazing optical material enables cost-effective uses for amateurs and professionals that were never before possible."