The Mark 25 sextant was developed with more features than the Mark 15. This model features a see through full field Beam Converger mirror and LED illumination that floods the arc and drum with soft light for reading sights taken in darkness. Includes carrying case and instruction booklet. Full field Beam Converger mirror LED light lights the arc and drum 3 X 27mm star telescope and 7 sun shades MODEL NO - 025