Color:Black Diamond Selector II" is a handheld electronic device used to distinguish real diamonds from other simulated stones. It was developed for fast, precise and safe diamond inspection. Functions: Pocket with a handheld. Operation simple and accurate. Emit audible tones for accurate readings. The diamond indicator is displayed when the stone is a REAL diamond (green light). Metal alert (continuous buzzing when user accidentally touches metal instead of stone). Big / small switch for testing diamonds +/- 8 points. To emit tones to get accurate readings. LCD display & LED display. If the stone is a fake crystal, a simulant such as cubic zirconium (CZ) will not react. Dimension: 16 x 4 x 2 cm Powered by DC 9V battery x 1 (not included) Package Included: 1 x diamond tester 1 x leather case 1 x test platform 1x User Manual