20mm Ultra wide angle 1.25" telescope eyepiece,13mm eye relief provide comfort and convenience 2. Ultra wide 68Degree apparent field of view gives you that unforgettable lost in space feeling 3. 5-Elements / 4-groups made of high index glass deliver sharp, high contrast vistas 4. Twist-Up eyecups, and barrels threaded for use with 1.25" eyepiece filters (M28.5*0.6) 5. Sleek black barrel with safety undercut to reduce the possibility of the eyepiece slipping out of the focuser or diagonal 6. Blackened lens edges, anti-reflection threads for maximum contrast