The quality of this sextant has been proven in many years of use by ocean-going navigators. Its optical system is designed to ensure maximum performance with a full 57mm index mirror. Interchangeable telescopes available in 4x40mm or 7x35mm.
Specifications: *Full 57mm index mirror *Rubber eye protector *Full illumination of both arc and drum *Carrying Case: double wall air molded plastic with two slide locks *Can be stored in fitted case with scope mounted *Interchangeable telescopes available in 4x40mm or 7x35mm (sold separately) *Measuring Range: -5 degrees to 90 degrees *Accuracy: Less than 18 seconds of arc *Telescopes: 4x40mm: angle of view - 7 degrees, relative brightness 100 or 7x35mm: angle of view 6.5 degrees, relative brightness 25. *Frame: Lightweight die cast aluminum alloy with corrosion resistant black finish & bronze arc *Vernier Scale: reads to 0'.2 *Index Mirror: (57x42mm) Aluminized on rear side *Horizon Mirror: 57mm diameter