A set of Baader 36 ? skimmer filters. Baader scopier filters allow you to obtain images in the H-Alfa, OIII and SII bands with the highest contrast at the shortest possible exposure times. Their narrow band has a transmission of over 90%. At the same time, it completely eliminates light pollution with anthropogenic light. The filters have been precisely precisely ground so that the surfaces are perfectly parallel and accurate to 1/4 the length of the wave over the entire surface. Multilayer dielectric coatings applied plasma and ionically cured are exceptionally hard and durable. The coatings in these filters are not damaged during normal use and cleaning.