How to use:
a). Press and hold the power button, red and yellow LEDs will light
b). Just exhale into the vent to get your BAC immediately
c). In about 20 seconds, the green LED will keep lighting for READY instead of red & yellow LEDs. The unit enters into the testing status.
• Green LED-below 0.02% Safe
• Yellow LED-0.02%-0.05% warning
• Red and Yellow LED-above 0.05%=Danger