This precision gauge estimates the weight and identifies gemstones with great accuracy. This gauge will compute weight from either direct measurements or data entered directly through keypad entry. Features specific gravity dictionary - simply enter the name of the stone and retrieve the data. Comes with a one year warranty and these features: measures 0-25mm, with .01mm accuracy; features direct carat conversion for round brilliant cut diamonds; power saving feature activated when placed on carrying case; includes battery, software, USB cable and protective carrying case.