Crucial CT2KIT25664BC1067 4GB 204-PIN PC3-8500 SODIMM DDR3 Memory KIT
In short, 204-pin small outline dual inline memory modules (SODIMMs) are the form factor used to provide DDR3 memory modules for notebook computers and other small form factor computing platforms. 204-pin SODIMMs are currently available in PC3-8500 (DDR3 1066MHz) speeds. To use DDR3 memory, your system must have both a 204-pin SODIMM slot and a chipset that supports DDR3 memory. A DDR3 SODIMM will not fit into DDR2 or DDR memory sockets. (Information about which memory technology your system uses is included in the Crucial Memory Advisor tool.)