Disclaimer: Acer is a registered trademark or Acer Incorporated 2GB 204p PC3-8500 CL7 8c 256x8 DDR3-1066 1Rx8 1.5V SODIMM. Genuine CMS brand, CMS is one of the most trusted names in the Computer Memory industry and this product carries a Lifetime Warranty from CMS Compatible with: Acer Aspire One D257-13404 Maximum Memory: 2 GB Expansion: 1 Socket(s) In order to upgrade to maximum memory, you have to remove the 1GB Module from the socket and exchange it with the 2GB Module