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A special Digital Gem Gauge named SmartPro Primo I (SPPI) has been developed to measure small dimensions accurately in millimeters and with direct conversion to carat unit (round brilliant-cut diamonds as the basic cut). It can also be used to estimate the weight of a gemstone (mounted or loose) by getting its dimension, Gem type, cut and Specific Gravity Constant which all of these are well programmed in the device to get weight estimation in Carat.

Download User Manual


  • Measures from 0.01 mm to 25.00 mm 
  • Measurement Accuracy 0.01mm
  • Digital millimeter (mm) and or cat (ct) display
  • Inner and outer Diameter Measurement 
  • Auto-Off Function 
  • Attachment for mounted jewelry
  • Weight Estimation of Gemstone in Carat with Specific Gravity
  • Zero settings at any position

Dimensions and Weight

  • Length:  126.72 mm (4.9 inches)
  • Height: 26.60 mm (1.04 inches)
  • Width : 60.35 mm (2.37 inches)
  • Weight: 138g 


  • 164 Gemstone types and 13 Gemstone cuts for weight estimation
  • 4-way switch with the center push for easy navigation
  • Front and Side slider to ease the sliding of gauge jaw 
  • Capable to measure the dimensions of gemstone even on flat
    surface (as table gauge)
  • Fast measurement display
  • Readable and clear OLED Display
  • Bluetooth Connectivity with IOS and Android Application (may use in getting weight estimation of diamond and issue certificates)
    Hold value function
  • Powered by rechargeable Battery or Micro USB
  • Overcharging circuit protection 
  • Battery indicator

Power and Battery

  • Press and hold the Power Button at the right side of Gauge to turn ON/OFF the device
  • SPPI has a built-in rechargeable battery as the power supply of the device.
  • if it is not turning ON, charge the battery using Micro USB Cable
  • The device will automatically be turned off during idle mode after 5 mins.


Operating Conditions

  • Operating temperature: 0° - 35°C (32°-95°F)
  • Storage temperature: -20° - 45°C (-4° - 113°F)

Include in package

  • SmartPro Primo-I
  • User Manual
  • Warranty certificate card
  • International Warranty card
  • Protective Carrying Case
  • Micro USB Cable