STEP 1 - CLEAN UP THE POLLUTANTS ? Before ozone treatments, please do some cleaning in order to remove the source of the odors. ? Close the windows and doors. STEP 2 - USE THE TIMER ?Insert the power supply. ? Set the control knob and leave the room. Treatment time can be adjusted according to the room size and air quality. ? If you are not sure, start with 15 min and increase as needed. ? The unit starts working and the indicator light is on. STEP 3 - UNOCCUPIED SPACE ONLY ? Make sure all occupants and pets stay outside the room being ozone treated. ? We include a NO ENTRY sign with each purchase which can be hung on the door as a warning. STEP 4 - AIR-OUT THE ROOM ? Upon returning to pick up the unit, make sure Timer dial is now in the "OFF" position. ? Air-out the treated area for a minimum of 30 minutes before allowing people or pets to re-occupy the space. ? If you notice any lingering odors, the area may be retreated at a longer duration.