De Lille said Idataroam developed the service as a way to solve the problem of high international mobile data roaming costs.
"We've travelled quite a bit ourselves and we know the amount of money you get slammed for internet costs.
"We are incredibly excited. We have had people looking at it in Australia and the US. We really want to be a roaming solution provider worldwide within a couple of years."
Hertz currently has 100 of the units in action and another 100 ready to go soon.
They can be recharged from a standard power outlet or in a car while travelling.
Users can connect up to five devices simultaneously, allowing shared access between passengers, and telephone calling costs can be avoided by using Skype.
The Wi-Fi gadget connects to the internet via mobile phone networks and coverage is over 97 per cent of New Zealand.
There is one package available, at a cost of NZD$12.95 + GST per day, but De Lille said other packages may be developed if the product is picked up overseas.
Idataroam is a 100 per cent NZ-owned company, backed and partially owned by interests associated with Stephen Tindall's K1W1 fund.