1GB KIT (2 x 512MB) For Gateway DS Notebook Series 400 Special 400E 400L 400S 400SD4 400SP 400SP Plus (Laptop) 400SP Special 400VTX 400X 400XL. SO-DIMM DDR NON-ECC PC2100 266MHz RAM Memory. Genuine A-Tech Brand. 1GB KIT (2 x 512MB) SO-DIMM DDR NON-ECC PC2100 266MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Gateway DS Notebook Series. (See Compatibility List Below)