The Explore Scientific 120deg. Series 9mm Argon Purged Waterproof EMD Coatings eyepiece really is in a class by itself. The 120deg. apparent field of view is unlike anything you have experienced before. Normally, when you look through hyper wide field eyepieces, you see a huge swath of the night sky at low magnification. With the 9mm 120deg., however, you see even more universal real estate, but you also see the main attraction, whether it is a nebulae, a galaxy, or a star cluster, close up and personal.
With such a wide field, you will also notice that objects stay in the field of view for a long time. This is especially noticeable when your telescope does not have a drive, like a Dobsonian or a refractor on a grab and go mount like the Explore Scientific Twilight I. Another great benefit of hyper-wide eyepieces is the ease with which you can gaze, not directly at an object, but slightly to either side. This skill, called using averted vision, is especially helpful when observing faint objects, because using averted vision puts the image on a part of your eye that is more sensitive to light, allowing you to see fainter images.