GraphicsStock is offering free downloads of the products for 7 days. The message says you can download anything which is available on the site, but there is a limitation of 20 Images/day. So it means you can have a maximum of 140 images from the website.
Another point is that, you will have to add a credit card to start downloading and after the 7 days time if you keep your account, your card will be charged. So make sure that you will remove your account on time if you are adding your card details.
If you are interested , go here and get them.