80 Degree Ultra Wide Fov Eyepiece: Experience celestial wonders with Astromania's swa 20mm eyepiece; featuring an 80 degree field of view; perfect for deep-space observation with 2" telescopes; it offers 30% wider views than standard eyepieces Multi-Layer Coating: Advanced 7 elements in 5 group lens structure minimizes distortion; anti-reflective broadband green film enhances contrast; Scratch-resistant coating ensures long-term performance for telescope eyepieces Universal 2" Standard with Filter Compatibility: Industry-standard 2” barrel (51mm) fits most modern telescopes; rear female threading accepts 2" filters & barlow lenses; rugged CNC-machined aluminum construction prevents light leaks Extended 24mm Eye Relief for Eyeglass Wearers: Generous 24mm eye-to-lens distance accommodates prescription glasses; twist-up rubber eyecup adjusts for individual comfort; parfocal design maintains focus when switching eyepieces Aluminum Alloy Material: This 2 inch telescope eyepiece is made of aluminum alloy and can withstand extreme temperatures; anodized surface resists corrosion & wear; ergonomic rubber eyeguard ensures comfortable stargazing sessions Astromania Fully Multi-coated 2" Ultra-Wide 80 Degree Eyepiece For Telescope - F20mm. 100% Brand New and High Quality. Multi-Coated 2" 80 degree F20mm UWA telescope eyepiece, packed in a protective plastic case. Barrel Size: 2". This superb ultra wide angle eyepiece has 80 degree field of view. 7-Elements in 5 Groups Design. Fully multi-coated, soft eyecup. The inside of the adapter is fully threaded to minimize reflections. Threaded for filters and Barlow lens: 2-inch standard female thread to fit a filter etc at the rear end, very well built. Focal Length: 20mm; Eye Relief: 24 mm; Design: 7-Elements in 5 Groups; Coating: Fully coated Broadband Green Film; Color: Ultra black design.