Orion Part #07710 - to fit 4.5" Newtonians and 120mm refractors
Inside diameter of 143.5mm
* A quality glass solar filter is essential to observe the sun safely with your telescope.
* Optical glass filter fits snugly over your telescope's aperture to block 99.999% of incoming sunlight
* Glass elements are machine-polished and triple-coated with nickel-chromium stainless steel
* Filter is mounted in an aluminum cell and supplied with foam tape liner and thumbscrews for secure fit
* Fits most 4.5" Newtonians and 120mm Refractors from Orion, Skywatcher and others.