Description Advanced semiconductor sensor with high sensitivity and fast response, simple and comfortable to use. It displays the final test result in digital mode and serial mode; anyone can check themselves with this tester. 5 result levels: excellent, normal, not very good, poor, very poor. Digital LCD screen with orange background lighting; energy-saving and environmentally friendly, with soothing colors that do not harm your eyes. Fast response and CV, with self-control to display different conditions. Portable design, compact size with a streamlined structure; easy to fit into a pocket and carry with you. Touch-free design, breaths 5-10 mm from the detector; more. Battery-saving design, low battery indication; 2 x AAA batteries provide long-lasting power (batteries not included). Usage: Open the battery compartment, insert 2 * AA batteries, and close the compartment. Press the button; it displays a 9-second countdown. Then the screen blinks C; at this moment, you can breathe evenly for 3 seconds at the intake. After a beep sound, the result appears; the result is displayed for 5 seconds and turns off automatically. If you want to test again, press the button once more. Specifications: Sensor type: semiconductor sensor Heating time: 9s Blow time: 5s Working environment: relative humidity less than or equal to 95% no condensation : 2 AAA batteries (not included) Product size: 95 x 36 x 18 mm / 3.74 x 1.42 x 0.71 in Color: white Material: plastic Package content: 1 x poor breathalyzer (without batteries) 1 x English instruction manual Only the above package content included; other products are not included. Note: Lighting and different screens may cause slight color differences between the item in the picture and the actual product. The allowable measurement error is +/- 1-3 cm.