Introduction:
This low power Omni eyepiece is a 4 -element premium symmetrical Plossl optical design. Features include blackened lens edges to minimize internal reflection and maximize contrast, multi-layer coating group on each lens surface to maximize light transmission and contrast, and each Omni goes through a two-step anodizing process to prevent reflection from the top eyepiece barrel, unlike most other manufactures who use reflective surfaces. Threaded barrels accept 1-1/4" thread-in filters.
Product carries two-year manufacturer limited warranty.
Features:
Celestron Omni series eyepieces offer a 50 degree apparent field of view, perfect for the Moon, planets, and a plethora of deep-sky objects. The premium four-element optical set is finished with multiple layers of high-transmission coatings for clear, sharp images. The edges of the optics are blackened for increased contrast.
The Omni eyepiece body is made of aluminum. A two-step anodizing process results in a beautiful matte f inish that resists reflections and glare.
Each eyepiece in the Omni Series includes a black rubber eyecup. It can be left up or folded down for better observations while wearing eyeglasses.
Models with a longer barrel (15 mm, 32 mm, 40 mm) include a rubberized grip for non-slip handling during observing sessions. The insert barrel is threaded to accept 1.25 inch filters.
Celestron Omni eyepieces are also available in the following focal lengths in a 1.25 inch format:
6 mm, 9 mm, 12 mm, 15 mm, 20 mm, 25 mm, 40 mm,Please check the link to buy them.  
 
Specification:
Omni 4mm eyepiece:
Focal Length: 4 mm (0.16 in)
Apparent Field of View: 50°
Eye Relief (mm): 6 mm (0.24 in)
Number of Lens Elements: 4
Barrel Size (in): 1.25 in (32 mm)
 
Omni 6mm eyepiece:
Focal Length: 6 mm (0.24 in)
Apparent Field of View: 50°
Eye Relief (mm): 5 mm (0.2 in)
Number of Lens Elements: 4
Barrel Size(in): 1.25 in (32 mm)
 
Omni 9mm eyepiece:
Focal Length: 9 mm (0.35 in)
Apparent Field of View: 50°
Eye Relief (mm): 6 mm (0.24 in)
Number of Lens Elements: 4
Barrel Size (in): 1.25 in (32 mm)
 
Omni 12mm eyepiece:
Focal Length: 12 mm (0.49 in)
Apparent Field of View: 50°
Eye Relief (mm): 8 mm (0.31 in)
Number of Lens Elements: 4
Barrel Size (in): 1.25 in (32 mm)
 
Omni 15mm eyepiece:
Focal Length: 15 mm (0.59 in)
Apparent Field of View: 50°
Eye Relief (mm): 13 mm (0.51 in)
Number of Lens Elements: 4
Barrel Size (in): 1.25 in (32 mm)
 
Omni 32mm eyepiece:
Focal Length: 32 mm (0.16 in)
Apparent Field of View: 52°
Eye Relief (mm): 22 mm (0.24 in)
Number of Lens Elements: 4
Barrel Size (in): 1.25 in (32 mm)
 
Omni 40mm eyepiece:
Focal Length: 40 mm (1.57 in)
Apparent Field of View: 43°
Eye Relief (mm): 31 mm (1.22 in)
Number of Lens Elements: 4
Barrel Size (in): 1.25 in (32 mm)

Package Included:
1x Celestron 1.25" Omni Plossl Eyepiece