100° 20mm Waterproof Eyepiece Focal Ratio_2. f/4.1 - f/6.5 1") aperture and 600mm focal

1") aperture and 600mm focal length (f/4

the compact 50mm aperture refractor is perfect for observing the Moon’s cratered surface

Item Number 310175 Filter diameter 1

Do not overtighten or the pin will no longer be spring-loaded

Retical Polar Alignment Crosshair

100° 20mm Waterproof Eyepiece Focal Ratio_2. f/4.1 - f/6.5 1") aperture and 600mm focalThese eyepieces with their huge apparent field of view not only gave the observer a panoramic visual experience, but they relax the eye so the observer could pay attention to subtle details for extended periods. These ultra wide angle eyepieces played a critical role in the military for aiming at targets, and their long eye relief counterparts helped reduce eye injury from recoil. Each 100 Series Argon Purged Waterproof eyepiece is internally sealed