The ESATTO 3" → Borg 90FL / 107FL f/3.9 adapter (PrimaLuceLab, SKU: PL3600268 ) allows you to replace the factory focuser of the Borg 90FL and Borg 107FL f/3.9 fast astrographs with a precise, remotely controlled ESATTO 3" focuser. The collar uses the original holes in the rear cell of the tube, so the mount is fully reversible and the design back-focus of the optical system is preserved.

The most important features of the adapter

• dedicated fit for Borg 90FL / 107FL f/3.9 astrographs – plug-and-play assembly
• maintaining the nominal back-focus of the structure – full compatibility with Borg reducers and flatteners
• full internal diameter 76 mm – no vignetting for full frame matrices
• CNC milled body made of 6061-T6 aluminum, hard anodized - lightweight, stiff and corrosion resistant
• blackened and grooved interior – effective reduction of reflections, better contrast

Set components

• ESATTO 3" ↔ Borg 90FL / 107FL f/3.9 flange adapter
• set of M5 stainless steel mounting screws

Technical parameters

• compatible telescopes: Borg 90FL (f/4) and Borg 107FL f/3.9
• compatible extractor: ESATTO 3"
• extractor thread (ESATTO side): M81 × 1
• optical thickness of the adapter: < 5 mm (does not affect back-focus)
• Inner diameter: 76 mm
• material: aluminum 6061-T6, anodized
• EAN: 8059020773335
• manufacturer: PrimaLuceLab – Italy

The PL3600268 adapter brings ESATTO 3" precision, automated focusing to high-speed Borg astrographs, providing a rigid, on-axis optical path and the convenience of remote control – key features in modern astrophotography.