This winged rubber eye shield from Baader is the perfect accessory for many different 1.25" eyepieces. The winged extension easily reduces excess light from reaching the periphery, and the wing can be rotated to the ideal position. When your eye is protected from light coming in from the side, it is easier to see faint objects. Nothing ruins a good view more quickly than a bright light skipping across the optical surface of the eyepiece! The Baader Winged Eyecup works wonderfully well for binoviewing as well. The winged extension folds down for more compact storage.