0.001g Precision Electronic Scales 100g/50g/20g Digital Weighing Gem Jewelry Diamond Scale Portable Lab Weight Milligram Scale Support USB plug-in power supply Specifications: Capacity: 20g/50g/100g(for the same tpye have 3capacities,you need choose one you need) Readability: 0.001 g Minimum weight:0.01g Errorrange:+-0.005g Weight units: g/oz/ozt/dwt/ct/gn/tl/mg Tare range: Tare full capacity Powered: 2 AAA batteries (not included) or USB plug-in(with USB cable) Auto-off: 180 seconds Platform size: 50mm Scale size (L x W x H): 110 x 63 x 15mm Net weight: 100 g Color: Black Key features: High precision: Accuracy of 0.001 grams, use I-shaped sensor, fast reaction speed, accurate and stable with large blue backlit LCD display, easy to read, compact size, portable, lightweight Unique windproof cover design, prevents external environment disturbance affecting the weighing accuracy Count (PCS button) function with accurate count and tare weighing function ensures more precise result and the hold function will lock weight reading Mini digital scale can be used as a jewelry scale, lab scale, diamond scale and carat scale, ideal for jewelry, medicinal herbs, lab, powder or other small things weighing Calibration method: After turn on,press "M" button,it will show"100.000"g(50g and 20g capacity is the same ),press "M" button again,it will show "CAL" then flashing"100.000",put the 100g weights on the pan,it will show "PRSS "then "100.000" (sometimes show 99.999 or 99.998,it doesn't matter), Calibration complete. Package includes: 1 x Jewelry scales(don't include battery) 1 x Tray 1 x Plastic tweezers 1 x usb cable 1 x Calibration weights