Combining excellent optics with a built in t adapter for astroimaging the ultima duo eyepiece from celestron has a wide 68 degree apparent field of view its multi coated optics are designed to increase light transmission and contrast and there are 8 lens elements in 5 groups to guarantee chromatic aberration and field curvature correction it will fit both 125 and 2 focusers so you can use it with almost any telescope simply remove the rubber eyeguard to expose the t threads and attach