In addition to the 2"focus of Bresser refractors, it can be used with any refractor or catadioptric system with a 2" focuser. The high quality Zenith mirror has the advantage of a wide metal clamping ring that is gentle on the eyepiece side accessories, and its three clamping screws prevent the eyepiece from moving out of the optical axis.
Reflectivity of its mirror is 93%, slightly higher than the 89-90% of an "average" music mirror.