Threaded for standard 1.25 inch astronomy filters and barlow lens
4mm plossl eyepiece: 4-element plossl design; has a approx 50 degree AFOV; lens coatings allow you to see objects brightly and clearly
Rubber eyecups protect against lateral stray light; long life - well made metal eyepieces
1.25 inch 4mm plossl eyepiece set; gives the widest viewing field along with extra sharpness and long eye relief
40mm plossl eyepiece: 4-element plossl design; has a approx 42 degree AFOV; perfect for broad-field lunar observations; medium-sized star clusters; and a wide range of cloudy nebulas and deep sky targets