The Astra IIIB has somewhat revolutionized celestial navigation. Never before has such a high quality, accurate metal sextant been available at such a low price. Over 18,000 sextants of this model have been sold in the US alone in the past 20 years; far more than any other serious sextant. Its popularity has spread throughout the rest of the world as well, making it the the most recognized (and supported) sextant worldwide.
It comes in a varnished wooden case, with instruction book, certificate of accuracy, and adjusting wrench. Case external dimensions are 6.5 x 13 x 11 inches. It includes a 3.5x40 monocular telescope as standard equipment.
SPECIFICATIONS | Arc | -5° + 130°, radius 153mm |
| Accuracy | ± 20", throughout the arc |
| Micrometer Drum | 1' scale, vernier to 0.1' |
| Horizon Mirror | 51mm diameter |
| Index Mirrors | 56x42mm |
| Shades | 4 index - 3 horizon |
| Weight | 2 lbs., 10 oz |
