A-Tech 4GB KIT 4 x 1GB IBM-Lenovo ThinkCentre M M58p 4099-xxx 6137-xxx 6138-xxx 6209-xxx 6234-xxx 6302-xxx 7188-xxx 7220-xxx 7346-xxx 7347-xxx 7357-xxx DIMM DDR3 NON-ECC PC3-8500 1066MHz RAM Memory 4GB KIT (4 x 1GB) DIMM DDR3 NON-ECC PC3-8500 1066MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For IBM-Lenovo ThinkCentre M Series. (See Compatibility List Below)