With a built in t adapter for astroimaging the ultima duo eyepiece from celestron is more than just an eyepiece with fittings for both 125 and 2 focusers it can be used with almost any telescope and has 8 lens elements in 5 groups to ensure that chromatic aberration and field curvature are corrected guaranteeing a sharp high quality result its multi coated optics are designed to increase light transmission and contrast and it has a 68 degree apparent field of view enjoy impressive vi