Please note: This text was taken directly from the manufacturer.
Our 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.