Vixen ED115S 115mm Diameter Refractor Telescope Optical Tube with Dual Speed.

The ED "S" apochromatic refractor features Extra-Low Dispersion (ED) glass in its objective lens to suppress chromatic aberration to a virtually invisible level. Coupled with a medium f/7.7 focal ratio, the ED "S" series provide a sharp, color-free image of high contrast for both visual and photographic applications. <
Works great with any Vixen equatorial mount.