Arch Memory 8 GB (1 x 8 GB) 204-Pin DDR3 So-dimm for Lenovo ThinkPad Edge E431 6277-5KU RAM Arch Memory is a Registered Trademark of Arch Computer, LLC 1 x 8GB DDR3-1600 PC3-12800 204-Pin Sodimm 1.5v Dual Rank (2Rx8) 1600MHz Lifetime Replacement Warranty Included