Full Details from Amazon.com : http://www.amazon.com/gp/product/B00MLQAX9E?tag=onigi-20

Laptop replacement backlit keyboard compatible with Dell Alienware M17X R3 R4 US layout Black

Layout US and backlit
Color Black
1 year warranty
There are several kinds of keyboard for the laptop models in the title This item is only compatible with the keyboard with DPN 08GWD6 02H8DG
If your laptop mainboard doesnt support backlit function the keyboard will work normally except the backlit