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) and PC3-10600 (DDR3 1333MHz) speeds.
Can not go wrong with Crucial9/11/2012
This ram worked great in a 2010 iMac and now my iMac is a lot snapper. It is amazing how much faster a machine feels with just a small ram upgrade. I have come to the conclusion after using a lot of different dims that if you get crucial dimms it will work. I am not sure the test done on crucial dimms but I expect it to be extensive as I have installed crucial dimms in all sorts of hardware and have never had any problem. I always seek out Crucal dimms when in need of ram.