2" / 50.8mm. Celestron 2" - 19mm - LUMINOS 82° Ultra Wide Angle Eyepiece parfocal wide angle eyepiece with excellent viewing characteristics. Celestron LUMINOS eyepieces convince by a very nice design and a high-quality multi-coated optics. In general, LUMINOS eyepieces offer a particularly well flattened image field with high sharpness up to the edge of the easily visible field of view. FIRING DISTANCE: 19 mm FIELD OF Sight: 82 ° Eye relief: 20 mm DIAMETER OF THE FIELD Aperture: 30 mm COATING: Fully Multi Coated OPTICAL DESIGN: 6 lenses DIAMETER: 2" PARFOCAL: Yes WEIGHT: 460 g