Brand new, never used. Imagine having two telescopes in one — a long focal length instrument for lunar and planetary work and a short focal length scope for deep sky observing and astrophotography. With the Celestron Reducer/Corrector Lens, that’s precisely what you get.

Focal reducer and field corrector lens accessory. Reduces the focal length and f/ ratio of your Schmidt-Cassegrain telescope by 37% Provides a dual focal ratio instrument, without sacrificing image quality!

Part number: #94175 Lens Coating: Fully Multi-coated Material: Machined aluminum Compatible: Celestron Schmidt-Cassegrain telescopes (C5, C6, C8, C9.25, C11, C14) | No EdgeHD tubes Dimensions: 56mm (2.2") in diameter, 34mm (1.34") long Weight: 4.3 oz (121.90 g)

Explicitly designed for Celestron Schmidt-Cassegrain telescopes, this unique lens reduces your telescope’s focal length and f/ ratio by 37%, turning your long focal length telescope into a fast, short focal length instrument. A f/10 focal ratio now achieves a f/6.3, while an f/11 focal ratio now achieves a f/7. For visual use, this means you get lower power with the same eyepiece and a wider field of view. Photographically you also get a wider field and much shorter exposures.

Depending on your setup it may require other accessories such as the Celestron T-Adapter for C5 - C14 Telescopes, shown here; https://www.highpointscientific.com/celestron-t-adapter-for-c5-c14-telescopes-93633-a