Hello everyone, my name is Brent and I learned to use computers on macs in school in the 80's. I have been a long-time windows user, but I just bought an old 2008 aluminum 20" 2.4 ghz iMac. I have used this site many times to look at the news and buyers guide, but I just registered. I want to add ram, but I would like some advice. I have the specs for the ram and this module looks right:http://www.amazon.com/gp/product/B0026SD96G/ref=olp_product_details?ie=UTF8&me= It's cheaper than the crucial and has prime shipping, so I was hoping this was the right one. It looks right to me, but I wanted to ask the experts here if there is any reason this isn't the right one. The crucial website says their chip is lead-free and halogen-free for the mac. The iMac has a 2gb chip in it and one free slot. I did a lot of looking around the internet and some people say they have bumped theirs up to 6gb, but other people say the memory should be even. One guy said he was able to put in two 4gb modules. I am thinking of playing it safe and just going with 4gb. Any advice?