Although created by Chinese company Huawei, Idataroam is the first in New Zealand to target the products at international travellers in the rental car market.
iDataRoam managing director Justin De Lille said the partnership is a landmark opportunity for his company in Australia.
"Breaking into Australia has been a goal for us, and to do so with a partner such as Hertz is extremely pleasing, continuing on from the success of the product in New Zealand."
He said the product could save travellers money as hotel Wi-Fi rates and mobile roaming costs remain "extremely high".
The devices connect to the internet via mobile phone and can be recharged from a standard power outlet or in a car while travelling.
Users are able to connect up to five devices simultaneously, allowing shared access between passengers.
In Australia, the units cost from AUD$12.00 (NZD$15) per day plus tax.
There is one package available in New Zealand, at a cost of NZD$12.95 + GST per day.
Idataroam is a 100 per cent NZ-owned company, backed and partially owned by interests associated with Stephen Tindall's K1W1 fund.