Explore Scientific engineered this 62° Series 9mm Eyepiece with a 6-elements in 4-groups lens configuration, anti-reflection fully multi-coated optics, and 12.6mm eye relief. This model of the 62°-series comes with a 1.25" diameter barrel that fits into common drawtubes, and accepts most eyepiece filters. The housing is argon-filled and O-ring sealed to be water and fog-proof, and has a textured ring on the exterior to give it a secure grip.