The Celestron 25mm Kellner 1.25" MC Eyepiece is a high-quality telescope accessory designed for telescopes with a 1.25" diameter. With a focal length of 20-29mm, this eyepiece provides clear and detailed views of celestial objects. Celestron is a well-known brand in the astronomy community, and this eyepiece is specifically designed to be compatible with Celestron telescopes. Mint in box, this eyepiece is a perfect addition for any telescope enthusiast looking to enhance their viewing experience.