The offer entitles you to 20% off the purchase price (excluding postage costs) on items at microsoftaustralia, up to a maximum discount of $1000 per transaction. A maximum of 2 transactions applies. Multiple items may be purchased in one transaction (up to a maximum of 10 items per transaction or total value of $1000). All monetary amounts specified in these terms and conditions are in Australian dollars (AUD).
Exclusions. This offer does not apply to items listed by the Selected Seller in the following category: Gift Cards (184609).
Full Terms and conditions available via link to deal
Edit: The deal page only lists 91 items, so here's a search link that lists 191 items
That tablet and PC section is pretty empty thought it would be full of Surface Book 2's given the upcoming update.
Samsung Galaxy Active would be down to $384 with the discount, not sure if that's a good deal or not.