Marine sextant
The marine sextant is a kind of reflection type angular measuring optical instrument.
1) Measuring the altitude of celestial bodies to determine the position of the ship at sea.
2) Measuring the two horizontal angles between three known position land objects to obtain the ship location on the chart by the help of a station pointer.
3) Measuring the vertical angle of a known altitude object to obtain its distance.

TYPE JD130-20 JD 130-40
Measuring Range -5~ +130 -5~ +130
Accuracy (peak to peak value) 20 40
The filters of Horizon glass 3 3
The filters of index mirror 4 4
Battery 2 x 1.5v 2 x 1.5v
Net weight 1.8kg bronze 1.2kg al alloy