The following William Optics ED APO Telescope are compatible with the William Optics FLAT6AIII Adjustable Field Flattener
- Amount of Adjustment:
- GT71 – 9.1mm
- GT81 – 7.1mm
- Z103 – 2.5mm
- Z81 – 5.2mm
- Image Circle:
- GT71 – 44mm
- GT71 – 9.1mm
- GT81 – 44mm
- Z103 – 43mm
- Back Focus:
- GT71 – 64.1mm
- GT71 – 9.1mm
- GT81 – 62.1mm
- Z103 – 57.5mm
- Z81 – 60.2mm
