Nebula Filter Oxygen III 1.25-inch Prism System_Roof please make sure you check

please make sure you check the Inside Diameter (ID) measurements of the assembly in question before you buy

and downloadable astronomy software to help you confidently locate and explore the night sky

Long Thumb Screw

This is very helpful to strong contrast differences compensate individually to various observation objects

Nebula Filter Oxygen III 1.25-inch Prism System_Roof please make sure you checkExplore Scientific Nebula Filter 1. 25" O III Range from 483nm to 511nm with peak at 496nm. Transmission 96. 7% Oxygen III This is the highest contrast Nebula Filter in the series, a line filter for only the two emission lines of oxygen. A great choice for observations of supernova remnants and other nebulae that glow in OIII. Other types of objects that glow in all parts of the visible spectrum (e. g. galaxies) are reduced visibly, but some normally