Celestron X-CEL Series 1-1/4 5mm Eyepiece 6-Element design using extra low dispersion (ED) glass on highly curved elements Fully Multi-Coated 55 degree apparent Field of View 20mm eye relief Soft Rubber Rolldown Eyecups Parafocal - Little or no focusing adjustment needed when switching from a low power eyepiece to a high power eyepiece More than 25mm of clear aperture