Orion Skyglow 2" broadband light pollution reduction filter for SCT. The filter screws directly onto the rear cell of the SCT.Costs $80 + shipping to buy new from Orion web site.
This one is in perfect condition.
I'm asking only $50 + $5 shipping in the continental US.
"The SkyGlow is an advanced multilayer 'interference' filter designed to enhance deep-sky observing in moderately light-polluted skies. It blocks the most common wavelengths of light pollution - predominantly produced by mercury vapor lamps - and allows higher transmission of critical hydrogen-alpha and hydrogen-beta lines. Bright, light-polluted skies appear much darker in the field of view and contrast significantly enhanced, particularly emission nebulas like the Orion and Lagoon. Views of galaxies and clusters are also improved." -- Orion web site