The Pentax PF-80ED-A Spotting Scope is a large and terribly impressive optical performer, with a brilliant 80mm objective lens and the ability to accept any 1.25 Inch astronomy eyepiece as well as 82mm filters at the front of the objective. It is 100% waterproof and fogproof, with durable rubber armour over an all-metal housing that's got a rotating tripod collar with detented stops every 45. The fully multi coated optics feature Pentax's well-regarded SMC multi coating process, and an element of ED (extra-low dispersion) glass helps provide razor-sharp edge delineation to high-contrast subjects.The PF-80ED-A's 1.25 diameter eyepiece specification allows less compacting of the light shaft produced by the objective lens, and thus a larger final image with superior depth perception. Any great 1.25 Inch eyepiece can be used, from Pentax themselves to elite telescope manufacturers' eyepieces such as Meade, Celestron, Vixen, and of course Tele Vue. The PF-80ED has a focal length of 518mm.The PF-80ED-A is amongst the very short list of premium spotting scopes that includes a view-through case as standard equipment. This valuable accessory is quite nearly a necessity, and is not included but rather an expensive additional option with the European-made units.- A superb large-class spotting scope with 45 angled viewing- JIS Class 6 100% waterproof & fogproof construction- Pentax's SMC multi coatings applied to every optical surface- An ED glass element to provide ideal colour correction and contrast- Accepts 1.25 Inch astronomy eyepieces- Rotating tripod collar with detented click stops- Retractable hood shields objective from stray light or moisture- Accepts 82mm filters- Includes a view-through caseSpecifications:- Objective Lens Diameter: 80mm- Minimum Focus Distance: 19.0 (5.8 m)- Weatherproofing: Waterproof & fogproof- Dimensions: 16.3 x 5.3 x 3.9 (415 x 135 x 100mm) WxHxD- Weight: 3.57 lb (1620 g)