How it works: is a product has been awarded another tariff (usually 5%) and the company feels it is a medical device, then you (or alternatively the company’s customs agent) can apply for a new tariff advice for a zero tariff.

This usually involves the product being assessed by a customs agent at the Customs Office at Sydney Airport.

More info on the following link:

http://www.customs.gov.au/tariff/tariff-advice.asp
To start the process it is also necessary to fill out a form:
http://www.customs.gov.au/webdata/resources/files/b102.pdf