4GB Total memory using 2pc of 2GB 1066MHz Module 240pin dimm DDR3 8500. 
Lifetime warranty for exchange. by Computer Memory Solutions
Brand Computer Memory Solutions

Max Memory: 16GB
Sockets for Upgrading: 4
Max memory per Socket 4GB
If 4GB is installed, the recognized memory may be reduced to 3.5GB or less (depending on system configuration and memory allocation). Maximum configurations require a 64-bit operating system.

MODULES MUST BE ORDERED AND INSTALLED IN PAIRS for Dual Channel mode

Compatible with the following Systems:
Lenovo ThinkCentre M58p 3063, 3285-xxx 
Lenovo ThinkCentre M58p 6137, 6138-xxx 
Lenovo ThinkCentre M58p 6209, 6234-xxx 
Lenovo ThinkCentre M58p 7188, 7220-xxx 
Lenovo ThinkCentre M58p 7346, 7347, 7357, 7358-xxx 
Lenovo ThinkCentre M58p 7483, 7484-xxx 
Lenovo ThinkCentre M58p 9964. 9965-xxx 

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