1GB KIT (2 X 512MB) For Sony VAIO VGN VGN-FS640/W VGN-FS640FP VGN-FS640QW VGN-FS645 VGN-FS645P/H VGN-FS650F VGN-FS660 VGN-FS660/W. SO-DIMM DDR NON-ECC PC2700 333MHz RAM Memory. Genuine A-Tech Brand. 1GB KIT (2 x 512MB) SO-DIMM DDR NON-ECC PC2700 333MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Sony VAIO VGN. (See Compatibility List Below)