Introducing Vixen's new SSW 5mm Ultra Wide ED 1.25 Inch Eyepieces that features an exceptional 83deg. wide field of view. The eyepiece's 7 element design, features high-transmission/low dispersion lanthanum and exotic glass. This combination offers unparalleled contrast and sharpness, outclassing all competing brands. Full multi-coating on all lens surfaces, in combination with special coating on the lens connecting surfaces, delivers high contrast sharp star images across the entire field of view. No edge darkening or vignetting is evident over the viewing surface, even with fast f/4.0 optics. The advanced multi coating on each lens surface offer high light transmission, over 99.5%, throughout the visible rays of light (430nm - 690nm) and produce extremely bright and clear images.Vixen Eyepiece Features- Anodized aluminum body- Hexagonal barrel with unique anti roll design- Sleeve design is applicable to both screw and compression ring eyepiece adapters- Retractable eye cup with rubber grip for great viewing and comfortable handlingSpecifications:- Focal Length: 5 mm- Barrel Diameter: 3.175 cm- Eye Relief: 13 mm- Apparent Field of View: 83In the Box:Vixen Optics SSW 5mm 83 Ultra Wide EyepieceModel: VX37122