Equipped with ultraviolet light to test flourescent reaction of stones Flexible calibration with multi Level Volume to match different sizes of stones An option to use or connect with A/C adaptor (not included) for long time indoor use Most compact design and low battery consumption Emit audible sounds to give warning buzzer if the probe touches metal surface Audible and visual indicator of genuine diamond With a single press of a button it can accurately and precisely:Supplied with vinyl pouch, testing platform for loose stones and a comprehensive instruction manual best utilize JEM-II Quickly distinguishes authentic diamond from all models of diamond simulants and metals Distinguish stones as small as 2pt and unused Complete set includes: 1 x Diamond Tester 1 x Vinyl Leather Pouch Case 1 x Heavy duty Testing Platform English Instruction Manual Probe Warm-up Time: about 25sec Working Time: about 5 hours for continuous use Suggested Working Temperature: 18C to 30C Working Voltage: 1 x 9V, 6F22 batteryor AC adaptor (110V-240V, DC 9V,not included) Size: 168 x 31 x 21mm Net weight: 55g