Davis Instruments Horizon Artificial. Use for backyard practice finding exact positon when inland and making exact sextant shot on foggy mornings. To use fill with water and read the angle of the reflected sun with your sextant. Half your sextant reading is the sun's angle above the true horizon. Windproof and corrosion resistant the reflecting surface is completely enclosed. Comes with two sun shades a lid and full directions. Compact 6" x 4" x 1-1/2" (15 x 10 x 4 cm). Specifications for Davis Instruments Artificial Horizon: Manufacturer: Davis Instruments Color: Black Package Contents: Davis Instruments Artificial Horizon Davis Instruments 144: Horizon Artificial