Celestron Luminos Eyepieces - 1.25" Size:19mm They can be considered "focal

They can be considered "focal reducers" for eyepieces

This allows the Etalon surfaces to always remain at the same perfect angle to the light waves but changes the diffractive index of the air in the chamber and thus accomplishes the same tuning expect that it goes around + or - 0

Product Dimensions: 16

Fits eyepieces up to 45 mm in outside diameter

ergonomic design for maximum comfort

Celestron Luminos Eyepieces - 1.25" Size:19mm They can be considered "focalAbout the Celestron Luminos Eyepiece 1. 25" The Celestron Luminos Eyepiece has a beautiful 82 degree field of view and offers a full range of viewing in comfort at a great price. What''s more, exceptional eye relief makes even eyeglass wearers happy! The Celestron Luminos Eyepiece 7 element fully multi coated optics are sharp and crisp. Experience excellent color correction and contrast! You'''ll enjoy features like a rubber grip ring, a hard anodized