- Measure over-pin diameter of gears
- Resolution 0.001mm/0.00005″
- IP54 dust/waterproof
- Button function: on/off, set, mm/inch, ABS/INC, data output
- Data output
- SR44 or LR44 battery, automatic power off
- Ratchet stop
- Supplied with setting standards (except 0-25mm/0-1″)
- Optional accessary: ball tips (code 7391, next page), data output system
| Code | Range | Micrometer head accuracy | Ball tips accuracy | L | b |
| 3591-25A | 0-25mm/0-1″ | 4μm | 8μm | 67 | 38 |
| 3591-50A | 25-50mm/1-2″ | 4μm | 8μm | 92.4 | 50 |
| 3591-75A | 50-75mm/2-3″ | 5μm | 10μm | 117.6 | 62 |
| 3591-100A | 75-100mm/3-4″ | 5μm | 10μm | 143 | 70 |
