12GB KIT (3 x 4 GB) For Alienware Area-51 Desktop Series ALX (DDR3) (3 Slots). DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory. Genuine A-Tech Brand. 12GB KIT (3 x 4 GB) DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Alienware Area-51 Desktop Series. (See Compatibility List Below)