2.4" 320 x 240 color multi-point capaciti-ve touch screen, easy and fast to o perate.3 Adopt British electrochemical sensor,accurate, fast and stable. The standard TYPE-C USB charging portis easy to use and reliable. The body is made of aluminum alloy and processed by CNC, withexquisite appearance. Large-capacity lithium-ion battery ensures long-term outdoor use. 7The concentration of the measurement result is divided into threecolors of red, yellow and green, and the concentration value prom pts. Can query measurement records, and store more than 20,000 records. The high-quality version can be blown more than 10,000 times.