GameStop has put up the product page for the DualShock 4 USB Wireless Adaptor, revealing some additional photos, including a few pack shots. You can check out the images of the PC and Mac adaptor for the official PlayStation 4 controller below this paragraph.
As you can see above, the accessory is used to connect the DualShock 4 wirelessly to the PC or Mac. Along with playing PC games, the PlayStation 4 controller can also be used for the PS4 Remote Play feature (which allows you to stream PS4 games from the console to the PC) as well as PlayStation Now (a streaming service for PS3 games).
In addition to GameStop, the DualShock 4 USB Wireless Adaptor is also available for preorder on Amazon, which you can check out with this link.
On Windows PC, Sony recommends using the device with the operating system of 7 (SP1), 8.1 or 10. The other recommended specs include 300 MB or more of free space, 2 GB or more of RAM, sound card, USB port as well as a CPU of 3.5 GHz Intel Core i3 or 3.8 GHz AMD A10 (or faster).
The DualShock 4 USB Wireless Adaptor has a listed release date set for the 19th of September in the North American region.