Series 5000 Super Wide Angle eyepieces boast a 68° apparent field-of-view and image resolution that is razor sharp from edge-to-edge. Because of their innovative six-element design, each eyepiece presents objects rich in detail and contrast with virtually no chromatic aberration.Features:16mm focal length68° apparent field1.25" ocular diameter, barrel threaded for filtersSix-element designPremium grade optical glassIndividually tuned, multi-layered coatings for maximum light transmissionEdge-blackened for optimum image contrastParfocal design limits refocusing when switching between eyepiecesAll Series 5000 Super Wide Angle eyepieces are made of the finest materials available and are a perfect optical match for Schmidt-Cassegrains, fast Newtonians and Schmidt-Newtonians. Each piece includes a soft rubber eyeguard – custom fitted to each eyepiece with a bayonet mount – that folds down for eyeglass wearers.