Ultrasonic Thickness Gauge, Includes Couplant, Protective Holster, Soft Carrying Case, Thickness Measurement Accuracy +/-0.001, Thickness Measurement Resolution 0.001 in, Calibration Certificate Type NIST, Maximum Frequency 5 MHz, Maximum Thickness Measured 5 in, Minimum Thickness Measured 0.04 in, Standards ASTM E797, Interface USB, Batteries Included Yes, Battery Chemistry Alkaline, Manufacturer Warranty Length 2 yr, Battery Size AAA, Battery Voltage 1.5V, Number of Batteries Required 3