Features: UT383 BT can effectively represent light intensity with electrical signals, then process data and display measuring results on LCD. Bluetooth function is added for data transfer and analysis on mobile App. Search for iENV and downloaded it from android or IOS App store. Light weight, user friendly interface. Voltage stability control technology, low power consumption. Light source calibration to increase accuracy and consistency. Specifications: Brand UNI-T Model UT383BT Functions Range Resolution Accuracy Illuminance 0~9999 Lux 1 Lux ±(4%+8) ≥10000 Lux 10 Lux ±(5%+10) ≥100000 Lux 100 Lux ±(5%+10) Measurement range 0~199,999 Lux; 0~19,999 Fc Sample rate 2/s Overload indication OL MAX/MIN Yes Data hold Yes LCD backlight Yes Auto power off 5 minutes Low battery indication 3.0~3.5V USB interface Yes Tripod mount Yes Battery Life >12hrs with Bluetooth function on Size 16.3*5.3*3cm/6.4*2.1*1.2in Weight 171g(approx.) Package Includes: 1 x Luxmeter 1、UT383 BT can effectively represent light intensity with electrical signals, then process data and display measuring results on LCD 2、Bluetooth function is added for data transfer and analysis on mobile App. Search for iENV and downloaded it from android or IOS App store 3、Light weight, user friendly interface 4、Voltage stability control technology, low power consumption 5、Light source calibration to increase accuracy and consistency