Explore Scientific 20mm 52° Series Waterproof Eyepiece

Looking for something out of the ordinary for your next eyepiece?  The Explore Scientific 52° series is a strong contender for necessary addition to your eyepiece collection. Looking for something out of the ordinary for your next eyepiece?  The Explore Scientific 52° series is a strong contender for necessary addition to your eyepiece collection.  It's long 15mm of  eye relief makes it a joy to put in your scope night after night. Often considered the perfect mid-range focal length for most amateur telescopes, the 20mm on the ED127 at f7.5 produces a 1 degree true field of view. Perfect for the Messier Marathon, or running down the Herschel Catalog. The 20mm 52° Series is also a good selection for most binoviewers with its relatively small size and magnification range. While some might question the need for Argon-Purged waterproof eyepieces, it is a nice concept knowing the inside of your eyepiece will be just as perfect as the day it left the assembly line.  No need to worry about dust, or cleaning solution, finding its way inside the elements.  These eyepieces are designed to be used night after night giving you complete peace of mind about their performance. Tech Details: Item Number EPWP5220–01 Focal Length 20mm Length 71mm Width 43mm Weight 181.4 grams; 6.4 oz. Barrel Size/Type 1.25" O.D. / Double Taper Eye Relief 15mm Field Stop Diameter: 18.2mm Coatings: EMD (Enhanced Multi-Layer Deposition) on all lens-to-air surfaces Lens Elements/ Groups 5 Elements in 3 Groups; Edge Blackened Filter Thread Fits Standard 1.25-inch Dia. Thread in Filters (1.125-inches x 42 TPI) Waterproof O-Ring Sealed Argon Gas Purged; Tested Under 1 Meter of Water for 30 Minutes Eyecup Removable Flip-Down Style Soft Silicone Rubber Lens Caps Slide-on Top and Bottom Materials Optical Glass; Aluminum; Steel; Silicone Rubber Markings Laser Engraved: Focal Length; Series; Serial Number; Brand   Tech Details:  Barrel Size 1.25" Eye Relief 15mm Field of view 52° Field Stop 18.2mm Focal Length 20mm Number of optical elements 5 Weight 6.4 oz Warranty 1 year