Excerpt: I used this to upgrade my Early 2008 MacBook Pro to the max 4GB of Ram. I was concerned at first that it wouldn't be compatable because it didn't say made for Mac on it but was assured by friends that it would work fine in my Apple product. They were correct! Installation was easy and everything went smoothly. I highly recommend this product.
Summary: We upgraded our early 2008 iMac to 4Gig but starting having performance problems with Mountain Lion and extreme slow downs after upgrading to Mavericks. Though it didn't appear to be a memory issue (limited swaps), we decided to go from 4 Gig to 6 Gig by swapping out one memory chip and it solved our problem. iMac runs almost like new.
Summary: I bougth it to increase the RAM up to 6GB, it suppose that it can go up to 4GB but I removed one of the 2GB and installed this new one and the computer inmediately went up to 6GB with no problem and high performance. I am very happy and recommend this module!!!!