Solomark 90mm Solar Filter, Baader Planetarium Film, for 90mm Celestron Aperture Telescopes Plastic - Prepare for the Solar Eclipse of August, 2017 This solar filter film could filter the sun's rays efficiently,allow you view the sun safety Two sides high density coating without streak and blister point ensure the safety of the user's eye High density coating aslo eliminate pinhole effect provide sun's true color neutral white,not blue or orange For Celestron 90mm Aperture Telescope or Other Telescopes Front End Tube Out Diameter Approximately and Less Than 112mm Optical density: 5.0 Aperture of the telescope