The top screen of the new device - which is to be known as 'Echo' - slides out and can be snapped into place so that the two lay side by side.
This means that the screen space of the new device will rival that of a tablet computer, the manufacturer explained.
Indeed, the screens create a large enough display for typing emails, playing games and watching videos.
However, the screen is still just around half the size of Apple's iPad.
Founded in 1937, Sprint Nextel is a US-based telecommunications firm.
The company owns Sprint, the third largest wireless communications network in the US, boasting 56.3 million customers.
It was renamed in 2005 with the purchase of Nextel Communications by Sprint Corporation.
