The Explore Scientific 3-inch Dielectric-Coated Diagonal Mirror comes complete with 2 inch Adapter and dust covers. Solid construction and light weight, this first surface coated diagonal mirror reflects 99% of the light to help maintain the brightest possible image from your telescope.

The insert barrel is a double taper, so it can be smoothly inserted or withdrawn from the focuser. The wide part of the taper prevents the diagonal from accidentally falling out of the focuser if the set screw loosens up. Eyepieces are secured in the diagonal with a compression ring lock on both the two-inch eyepiece holder and the 1.25-inch eyepiece holder (1.25-inch eyepiece holder sold separately).