The Presidium 100n Carat Scale is the latest innovation of carat weighing technology, utilizing Advanced Circuitry Design and Surface Mount Technology (SMT). This new scale doesn't have to be calibrated each time it is turned off. This portable carat scale promises reliability and consistency for long periods of continuous usage. Designed specially for jewelry traders on the move by the leading maker of gemological instruments, its compact size and rugged build allow for easy-to-travel usage and durability.