This is Helio’s Pantech PN-810 dual slider phone. The Pantech PN-810 has a 2.1 Megapixel camera, QWERTY keypad, Bluetooth support, built-in media player.
The PN-810 has “two distinct layers to provide two completely different keypads depending on the slide direction: QWERTY in one, numeric in the other”.
[Engadget]