The CaF2 Fluorite Flatfield Converter (FFC) is arguably the best and most sophisticated Barlow lens in the world. Designed for uncompromising sharpness in lunar, planetary, and solar observation. Its unique, apochromatic 4-lens system with two genuine fluorite lenses (CaF2) delivers ten times the line resolution of even top-tier projection eyepieces. The FFC offers a flexible focal length extension from 3x to 8x (expandable to 2.5x-15x) while remaining absolutely sharp over an image circle of 90 mm. Thanks to high-quality HT multi-coating, temperature-compensated housing, and precise manufacturing in Germany, it sets standards in transparency, contrast, and imaging performance. This set includes all necessary adapters for visual use and astrophotography, including a 2" socket, ClickLock® clamp, T?2 quick changers, and extension tubes for fine-tuning the magnification factor. The FFC fits any T?2 thread and any 2" eyepiece holder, making it universally applicable.