Explore Scientific 20mm 100 Degree Eyepiece Features: Coatings: All lens-to-air surfaces are fully multi-coated, edge-blackened Eye Relief: 14.5mm Body: Anodized Black Aluminum; Laser-Etched
Barrel: Stainless-Steel, 2-inch, Double Taper, Accepts Standard 2-inch Filters Eyecup: Rubber Folding Type Nitrogen-Purged and Waterproof: Internally sealed and purged with inert, dry nitrogen gas to prevent internal fogging, to halt the intrusion of fine particulates and fungus, and to maximize the life of the internal coatings. To make sure, each eyepiece is tested by submerging each unit in 1 meter of water for 30 minutes.

Comes with bolt style case.

The Explore Scientific 100° Series 20mm Eyepieces revolutionize the world of visual astronomy, presenting a sweeping apparent field of view that immerses observers in a panoramic and captivating celestial experience.

For reviews see: https://stargazerslounge.com/topic/292751-explore-scientific-20mm-100-degree/ Review https://www.amazon.com/Explore-Scientific-100%C2%B0-20mm-Eyepiece/product-reviews/B0031R4XM0 From a review on the Explore Scientific web site: This is my #1 eyepiece, along with my 2 in. x2 Barlow this this pretty much all I ever use. I’ve been a visual observer for almost 25 yrs and have seen through a lot of eyepieces. I’ve found Explore Scientific products to be top-shelf quality. Fantastic eye relief, incredible field of view, pinpoint stars to the edge. M51 in my 20 in dob is jaw dropping.

New price is US$800 from Explore Scientific - plus GST and freight.