For precise linear measurements, consider the Origin Digital Caliper from iGaging, which uses ABSOLUTE memory technology. It keeps track of its origin position once set. Whenever the digital caliper is turned on, the easy-to-read large LCD displays the actual sensor position ready to start measuring. It's not necessary to reset zero, and the measuring speed is unlimited.
This quality caliper competes directly with the top name brands but costs about $100.00 less.
Here are the particulars:
Range: 0-6" (0-150mm)
Resolution : 0.0005" / 0.01mm
Accuracy : 0.001"/ 0.02mm
IP54 Protection Rating (Humidity and dust resistance)
Fractional / Decimal Equivalent on back of Caliper
3V CR2032 Battery (spare included): Lasts more than two years under regular operation