Celestron X-Cel LX series eyepieces offer a 60 apparent field of view, perfect for the Moon, the planets, and a plethora of deep-sky objects. The premium six-element optical set is finished with multiple layers of high-transmission coatings for clear, sharp images. The edges of the optics are blackened for increased contrast. All seven X-Cel LX eyepieces sport 16mm of comfortable eye relief, and are parfocal, which means you can switch out eyepieces within the series during observing sessions and little or no additional focusing will be required. The X-Cel LX eyepiece body is made of black-anodized aluminum. The pop-up eyecups make it easy to adjust the height for different users. Turn them in one direction to extend the length, and the other direction to provide a flat surface, preferable to most eyeglass wearers. A threaded rubber grip around the center of the eyepiece barrel offers secure handling, even in moist conditions or with heavy gloves on. The 1.25" insert barrel is threaded to accept filters.