Dual-Observation System for Zeiss Universal / Junior / Standard / Others - Grey
Standard 43mm dovetail mount.
Two different style heads - one where the interpupillary distance is adjusted by sliding in/out, the other, the angle between eyepiece ports is changed to adjust interpullary distance. Also, one has two focusable eyepiece ports, the other has only one...no real disadvantage.
4 - 8KPL Highpoint eyepieces / 23.3mm diameter (work with glasses on)
For internal pointing arrow to work, you need an illumination system - otherwise works fine.
Diameter of light-receiving port on the dual head block is 11.6mm
There's a lever on the side where the arrow controller is which flips in a colored filter I believe./