GM100 Ultrasonic Thickness Gauge - Digital Measuring Instrument Specifications: Transducer: 10mm 5.0MHz transducer Display: 4-digit LCD display Minimum Display Unit: 0.1mm Working Frequency: 5MHz Measuring Range: 1.0 to 225mm (for steel) Minimum Pipe Measurement Limit: 20x3mm (for steel) Accuracy: (0.5%H + 0.05)mm (H denotes measured thickness) Sound Velocity Range: 1000 to 9999 m/s Sound Velocity Measurement Accuracy: For thickness over 20mm: 5% For thickness under 20mm: 1mm/H x 100% Operating Temperature: 0 to 40 Power Supply: 3 x 1.2V rechargeable Ni-MH batteries Operating Current: Normal: 50mA With Backlight: 120mA Standby Current: 20A Size: 65 x 146 x 30mm Backlight: Yes Data Storage: Up to 500 readings Package Contents: 1 x Ultrasonic Meter 1 x 5Md10 Probe 1 x Hard Shell PP Plastic Carrying Case 1 x USB Cable with Adapter 1 x Empty Bottle 1 x Manual Notes: Measurement methods may cause a variance of approximately 2-3 cm, which is not a quality issue. (1 inch = 2.54 cm) Due to varying lighting conditions and screens, the actual product color may differ slightly from the displayed images. Please refer to the actual product for the true color.