The GemOro AuRacle Analyzer tests all colors of gold from 6K to 24K with 20% IMPROVED ACCURACY over previous models. This unit also features increased accuracy when testing high-karat gold. Follow simple steps to identify non-gold, gold plate, and gold-filled as NA Easy one-button operation. User-friendly instructional display Calibrates with 18k yellow gold (not included). Immediate test results—no waiting between tests. Simply file the gold/platinum, then touch the pen probe to the filed area and an LED indicates the karat value. The enhanced Pen Probe features Faster testing results, Faster calibration and longer time between calibrations. Pen probe performs thousands of tests with proper care. This unit is compact and portable. Powered by a 9V alkaline battery (not included) or the supplied 100V-240V multi-voltage adapter. Includes: Analyzer, pen probe, file, and AC adapter.One-year limited warranty – PATENTED