32GB KIT (4 x 8GB) For IBM-Lenovo Thinkpad Notebook Series W520 (4 Slots) W530 (Quad Core). SO-DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory. Genuine A-Tech Brand. 32GB KIT (4 x 8GB) SO-DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For IBM-Lenovo Thinkpad Notebook Series. (See Compatibility List Below)