The Oculus Rift Development Kit 2 (DK2) is a hardware kit made available to developers that want to create virtual reality content and experiences for the consumer version of the Oculus Rift.
The DK2 was announced in March of 2014 at the Game Developers Conference in San Francisco and began shipping in July 2014. In February of 2015 Oculus announced that over 100,000 DK2 units have been shipped to developers.
The DK2 features an OLED display with a 960x1080 pixel resolution per eye and positional tracking. The display in the DK2 uses a Samsung Galaxy Note 3 pane, presumably to save costs.
A desktop computer running Windows 7 or Windows 8, 2 USB 2.0 ports (at least one powered), and a dedicated graphics card Nvidia GTX 600 series or AMD Radeon HD 7000 series (or better) with DVI-D or HDMI graphics output.
In addition to the minimum spec it is recommended that your dedicated graphics card be capable of running current generation 3D games at 1080p resolution at 75fps or higher.