The Pentax PF-65EDA II Scope is designed for high-precision outdoor viewing, and has now been improved over its predecessor by further minimising colour aberrations, resulting in truer colours.These scopes use 1.25 diameter eyepieces, which allow less compacting of the light shaft produced by the objective lens and thus a larger image with superior depth perception. This is a great feature, for in addition to the brilliant of/erings from Pentax themselves it also means you can use the best of astronomy eyepieces from elite telescope manufacturers such as Meade, Celestron and of course the venerable Tele Vues. The PF-65EDA II has a focal length of 390mm, so if you're using conventional 1.25 Inch eyepieces you divide 390mm by the focal length of your eyepiece to determine the effective magnification. Pentax ED scopes function brilliantly in many conditions of light and climate, and are remarkably light thanks to their metallic alloy housing.Pentax's scopes are available in either a straight viewing or angled viewing depending upon your needs. This is a personal preference, which cannot easily be defined for you until firsthand experience, but the conventional thinking is that the scopes with angled viewing provide superior comfort during long observations as well as easy simultaneous use amongst those of differing heights-which is quite difficult with a straight viewing design scope.- Porro prism design with Pentax's trademark Super MultiCoated optics- JIS Class 6 waterproof & fogproof construction- American standard 1.25 Inch (31.7mm) thread diameter allows use of many telescope eyepieces- Rotating tripod collar with detented click stops- Retractable lens hood- Accepts 67mm filtersSpecifications:- Objective Lens Diameter: 65mm- Minimum Focus Distance: 16.4 (5.0 m)- Weatherproofing: Waterproof & fogproof- Dimensions: 10.6 x 4.7 x 3.3 (270 x 120 x 85mm) WxHxD- Weight: 2.36 lb (1070 g)