on that link it says it is for a credit card
see below
Westpac announced a brand new offer this week for anyone taking out their new credit card. They're going to give you six month's worth of retail purchases on it with a capped interest rate of just 4.99% p.a.
I think it's a great solution if you like to start early and get everything in and have less of a headache once January statements start dropping through the door. When your six months is up, your Westpac Low Interest MasterCard, as they're calling it, will change to their standard interest rate (currently 12.95% p.a.). The card's on offer now but if you want one, be quick to apply because this offer is for accounts opened before the end of this month.
Does this appeal to you? I like it.