Color eyepiece filters enhance subtle details on the planets, comets, and the Moon by selectively increasing the contrast between markings of different hues. This affordable 1.25 inch Basic Set of Four Color Filters includes our most popular color planetary telescope eyepiece filters: 15 Deep Yellow, 25 Red, 58 Green, and 80A Medium Blue. These filters are vat-dyed for even color coating and then anti-reflection coated for maximum transmission. The eyepiece filter cells are made of anodized aluminum and are double-threaded to permit filter stacking. A protective plastic filter case in included.