[WIDE RANGE MEASUREMENT] The refractometer offers a wide measurement range suitable for various sugar-containing substances. [HIGH ACCURACY] With 0-50% high range detection, this refractometer provides precise and accurate readings. [PORTABLE DESIGN] Compact and stylish, this refractometer is easy to carry anywhere for on-the-go testing. [TEMPERATURE COMPENSATION] Equipped with automatic temperature compensation from 10 to 40 for consistent results. [POWER SAVING] Features automatic power-off function after 3 minutes of inactivity to save battery life. Item Type:Refractometer Size:.121x58x25mm/4.76x2.28x0.98in Weight:.313g/11oz Range:0 to 50% /0 to 80 Resolution:0.1% /0.1 Accuracy:0.2% /0.3 Automatic Temperature Compensation:10-40 Measuring Time:About 1.5 seconds Minimum Sample Size:2 metric Light Source:Yellow LED Power Supply:1 x AAA battery (not included) Start using after installing the batteryCalibration method: The instrument only supports pure water calibration. The calibration method is as follows: 1. Drop 4-5 of purified water into the drip opening 2. Press the Calibration key for 2 seconds to enter the calibration state. 3. Press the Calibration button once to start calibration.If you don't press any button, it return to the power-on state after 10 seconds. 4. After the calibration is completed, you can put the liquid to be measured on the drip port, close the lid, and the reading be displayed for a moment Colour:As Shown Material:Plastic Package Contents: 1 x Refractometer(Battery Not Included) 1 x Dropper 1 x Protective Case Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.