Agena 1.25" 20mm 70-deg Super Wide Angle SWA Eyepiece # SWA20 Telescope eyepiece with 20mm focal length and wide 70 degree apparent field of view 16mm eye relief, fold-down rubber eyeguard 1.25inch barrel diameter, threaded for standard 1.25" astronomy filters Weight 4.2oz Fully multicoated lenses and blackened lens edges