Orion 8884 3.0mm Edge-On Planetary Eyepiece Description Features: 3mm 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 Product Details: Brand: Orion Objective Lens Diameter: 20 Millimeters Focus Type: Manual Focus Finderscope: Reflex Focal Length Description: 20 millimeters Objective Lens Diameter: 20 Millimeters Focus Type: Manual Focus Finderscope: Reflex Focal Length Description: 20 millimeters Brand: Orion