NP900X4C-A01US. 15" 1600x900 screen. Very light at 3.5 lbs and thin at .59". In amazing shape. Fresh windows 7 64bit installed and activated. Comes with windows 7 key. Core i5-3317u dual core with 8 gb ram. Ram and hard drive are upgradeable on this model via diy. Backlit keyboard, sd card reader, Wi-Fi, USB 3.0, Bluetooth, all included. Includes factory AC charger. Never had any problems, just upgraded to a newer model. Only minor issue is you can see the shadow of a prior install of a transformers sticker on the outside front of the shell.