Item Type: Air Quality Detector Model: JMS10 Display: LED Digital Display Battery: AA x 2 ( Shipped Without Battery ) Detection Principle: Semiconductor Gas Sensor Principle Detection Range: 0.000-9.999mg/m3 Detection Range: 0.000-9.999mg/m3 (TVOC) 0.000-2.888mg/m3 (HCHO) 1LED Digital Screen: This air tester features a LED digital screen, making it easy to work at night or in any dark place. 2Compact And Portable: This air tester is small in size and light in weight, which makes it very convenient to carry around and use. 3Easy To Operate: This air tester is easy to operate, you can test the air anytime and anywhere to get accurate data, and quickly calculate the output of accurate measurement results in complex environments. 4Settable Alarm Thresholds: This air tester can be set with upper and lower alarm thresholds. When the measurement is higher or lower than the set threshold, the red background light on the screen will light up and the measured value will flash as an alarm. 5Wide Application: This air tester has a wide range of applications and can be used in living rooms, bedrooms, offices and hotels. 1 x Air Quality Detector 1 x Manual