Operating Principle:P-E (pulse-echo) with dual-crystal probes Measuring Range:0.03'' to 12'' in standard mode Storage:5 arrays are divided to store 500 thickness values Repeatability:0.001'' Display Resolution: 0.001inch Units:Inch or Millimeter Update Rate:4Hz Measuring Error: Low limit to 0.4'': +-0.004'' 0.4'' to high limit: +_ (1%H+0.1) mm Note: H is the actual thickness of the testing material Operating Time:Up to 200 hours with alkaline batteries (without backlight) Instrument Shut-off:AUTO OFF after 5 minutes of inactivity Power Requirements:Two 1.5V AA alkaline batteries (Warning with low battery voltage) Operating Temperature:14°F to 122°F, 4°F in special requirements