The filter unit contains 2 filter wheels with 6 filter stacks each with an optically free diameter of 62 mm. The filter unit can be attached to the four side ports and to the main port.
- Wheel 1 is free for use by the astronomer with changeable filters with a thickness up to 5mm. There are 6 filter adapters, which can easily be disassembled from the wheel.
- Outside of the filter unit the required filter can be mounted. A protection ring fixes the filter inside the adapter. Then the adapter can be assembled back to the filter wheel by fixation of one screw.
- Wheel 2 is occupied with filters U, B, V, R, I and a neutral glass with a thickness of 3mm and an optically free aperture of 64 mm.