1GB KIT (2 x 512MB) For Toshiba Satellite A Series A105-S2011 A105-S2021 A105-S2031 A105-S2051 A105-S2061 A105-S2071 A105-S2081 A105-S2091. SO-DIMM DDR2 NON-ECC PC2-4200 533MHz RAM Memory. Genuine A-Tech Brand.