Full Details from Amazon.com : http://www.amazon.com/gp/product/B000R55IPU?tag=onigi-20
Crucial 4GB Kit (2GBx2) DDR2 667MHz (PC2-5300) CL5 Apple Fully Buffered ECC FBDIMM 240-Pin
Increases system performance
Easy to install
Premium quality memory from a trusted brand
100 Tested
Limited Lifetime Warranty