The inside diameter of this filter is 133mm or 5.25 inches. This is suitable for some Celestron 102mm refractors, and other telescopes. Please check the outside diameter of your telescope tube before ordering; the filter must be a snug fit or it may fall off.
Made with high quality hand select glass coated with our exclusive Solar II Plus. The most durable glass filter on the market. Transmission is 1/1,000th of 1 percent (Optical Density 5). Great for both visual and photographic use. Solar image is yellow-orange. Guaranteed fifteen years.
This filter is completely safe for unlimited visual use. If handled with care and common sense, it will last a minimum of 20 years to life.
All the heat and intense light is blocked before it can enter the telescope. Your telescope may get warm from sunlight shining on it, not from the small amount of visible light transmitted through the filter.Sunspots and surface granulation are the two main features. The only detail that cannot be seen with a standard filter (commonly called white light filter) are prominence and flares which require our highly specialized H-Alpha filter system.