... exhale into sensor for 3 to 5 seconds , after finishing Countdown ,display screen will show the ... to alcohol or alcohol content normal,the LCD screen keep green 5.If test report can ... reach to the scope below ,the LCD screen change to yellow and “Caution” will show .√ ... driving for the safety of yourself and others pls. New arrival, Backlight Alcohol Tester for iPod touch5,iPhone5,iPad4,iPad mini