From the Manufacturer3mm high-magnification 1.25" eyepiece designed for exceptional planetary and lunar viewing. Flat field design ensures sharp focus out to the edge of the wide 55-degree apparent field of view. Edge-On eyepiece design eliminates barrel distortion and field curvature commonly seen in standard eyepiece designs. Each Edge-On Planetary eyepiece has long 20mm eye relief for comfortable viewing even with eyeglasses on. Ideal eyepiece for high-power viewing of the planets and Moon