Use this German-made Astronomik multi-coated (MC) Glass Filter if your imager's focal plane needs to remain parfocal with other Astronomik filters. Multi-coating prohibits undesirable reflections.
The MC Glass Filter substitutes for a UV-IR blocker provided your system doesn't have refracting elements. The Astronomik MC Glass Filter shields your imaging system from dust. The scratch resistance and substrate quality of the MC filter is identical to that of all other Astronomik filters plus it has multi-coatings to prevent unwanted reflections.