4pc of 4GB PC3-8500 CL7 16c 256x8 DDR3-1066 204pin SODIMM. Lifetime exchange or repair warranty against manufacturing defects. by Computer Memory Solutions Brand Computer Memory Solutions We don't use Generic module to avoid incompatibility. Guaranteed to work in your notebook or you get your money back. Compatible with: Compatible with Dell Precision Mobile Workstation Covet M6400 Maximum Memory: 16 GB SOCKETS: 4 MODULES MUST BE ORDERED AND INSTALLED IN PAIRS for Dual Channel mode, if supported. 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.