Arch Memory 4 GB (2 x 2 GB) 240-Pin DDR2 UDIMM PC2-5300 DDR2-667 RAM Arch Memory is a Registered Trademark of Arch Computer, LLC 2 x 2GB DDR2-667 PC2-5300 240Pin UDIMM CL5 Dual Rank (2Rx8) Non-ECC Unbuffered 667MHz Lifetime Replacement Warranty Included