A-Tech 8GB KIT (2 x 4GB) For Samsung R Series Notebook R540-JS01AU R540-JS03AU R540-JS09 R540-JS0A R540-JS0B R580-11 R580-i5-430 R580-JBB2 R580-JS01 R. SO-DIMM DDR3 NON-ECC PC3-8500 1066MHz RAM Memory at Amazon.com
Specs Samsung R R580 39.6 cm (15.6") Intel® Core™ i5 i5-520M 4 GB DDR3-SDRAM 500 GB NVIDIA® GeForce® GT 330M Windows 7 Home Premium Black, Red Laptops (NP-R580-JS03AT)