Features 1、The sextant is an accurate angle measuring instrument, which consists of three parts: the frame body, the optical system and the angle reading device. 2、The optical system includes a telescope, a moving mirror, a fixed mirror and a filter; the angle reading device has an indexing arc, an index rod, a drum wheel and a vernier scale. 3、These components are mounted on the frame and the optical system and the angle reading device are integrated into one unit via the indicator rod. 4、The sextant is based on the principle that the geometrical "outer angle of the trigonometry is equal to the sum of the two adjacent inner corners", "the angle of the parallel line is equal", and the "central angle can be measured by the arc distance of the circle". 5、Professional manufacturing, stable performace, high reliability. Specification Condition: Brand New Item Type: Marine Sextant Color: Black Measurement Range: -5 - +130° Measurement Accuracy: GLH130-40-40 Angular Seconds Identification Rate: 8.75 Angular Seconds Telescope: Magnification: 3.5X, Field of View: 5° Objective Lens Through-Light Diameter: Approx. 40mm/1.5in Exit Pupil Diameter: Approx. 11mm/0.4in Lighting Voltage: 3V Operating Temperature Range: -30-50°C Instrument Weight: Approx. 1.2kg/2.6lb Battery: 2 x AA Battery (Excluding) Package List 1 x Sextant 1 x Telescope 2 x Keys 1 x Brush 1 x Wipe Cloth 1 x User Manual 2 x Screwdriver 1 x Calibration Card 1 x Certificate