Thanks for purchasing our AAT088, a hand-held Digital Alcohol Breath Analyzer. AAT088 gives you a digital reading of your breath alcohol content and your possible concentration of alcohol intoxication .. Important: To begin, rinse your mouth with fresh water before using the device. Abstain from smoking or drinking for at least 15 minutes. If you perform a test just after drinking, the reading will fluctuate from very high to low reading (i.e. it will drop gradually). It is due to the alcohol residues inside your mouth that effects the test values. This will also happen with aromatic drinks, alcoholic mouthwashes or mouth sprays,medicines or drug, as well as by burping and vomiting. Please read the full instructions carefully for proper use of the AAT088 unit. Never drink and drive - the only safe level is zero - Battery Power AAT088 comes with a built-in 3.7V Li ion battery (300mAH) and please fully charge the tester before use. Attention: The reading is invalid if the battery power is low. When there is not enough battery power, the "Lo" & "bRt" will flash alternatively. Please charge the tester immediately. Please connect the provided USB cable and charge the machine. The "LOGO" will turn into red color. The red logo will turn off when the battery is fully charged. Insert the provided Mouthpiece into the gas inlet located aside of the LCD screen. Instruction - How to power on and start breathalyzer test (1) Press the Key to turn on the power and enter into the alcohol mode, "Wait" will turn on. If the machine has already been turned on, just press ( Key once to activate sensor pre-heating, [ PH ] will flash for few times and then start a 19 sec. countdown. When countdown to zero, it is ready to start alcohol test. (2) "BLOW" flashes with beep tone and it is ready to take sample. There will has a 5s count down period for auto detect function. You can either do 2.1Manual Test or 2.2 Active test 2.1 Manual Test (if do not drink alcohol or at very low concentration) Press the Key once, "BLOW" lit on. Please start to blow through the mouthpiece steadily and continuously for approximately 5 seconds. 2.2 Active Test Please blow in within the 5s auto detect period. If alcohol detected, "BLOW" lit on. Please blow through the mouthpiece steadily and continuously for approximately 6 seconds. If there is no alcohol detected within 5s auto detect period AAT088 will take about 5s sampling as well and will then show the reading. While blowing, a long beep will be heard and please keep blowing. When the beep tone stops, sampling finishes and the test result reading will be shown on the display immediately. -How to power off: (1) Auto off, the machine will turn off automatically if no key being press for about 25 seconds. (2) Manual, press and hold the @ key for 1 second to power off the machine when display show "ALE ".