Please note: This text was taken directly from the manufacturer.
Orion's color telescope filters will enhance your view of the planets and Moon, enabling you to see more detail! They selectively increase the contrast between markings of different hues and reduce "irradiation," the smudging of boundaries between light and dark regions that results primarily from turbulence in the Earth's atmosphere. Indistinct features suddenly become distinct! Perfect for astrophotography. Orion color telescope filters are made from high-grade Schott optical glass and vat-dyed for even color coating, and then given an anti-reflection coating. Their anodized aluminum cells are double-threaded to permit filter stacking and are labeled with their Wratten filter number. Available in 1.25" and 2" sizes.