Our email (see Step 2 in the "Breathalyzer Trade In Process") will include a reply paid return label attached as a PDF.
You will need to download the PDF and print it. (If you don't have a printer, you can show it to the Australia Post counter staff and they will be able to print it out for you at the post office).
You need to pack your breathalyzer up securely in a padded bag or box.
Then, just paste the printed out return label onto the packaging and drop it off at the post office.
Our return label has a tracking number so we can track its delivery back to us.