4.0GB Samsung PC3-10600 DDR3 1333MHz SO-DIMM 204 Pin SO-DIMM Memory Upgrade Module at Amazon.com

4.0GB Samsung Factory Original PC3-10600 DDR3 1333MHz SO-DIMM 204 Pin CL9 SO-DIMM Memory Upgrade Module for 2011 MacBook Pro(all sizes), Mid 2010/2011 21.5" & 27" iMac, Mid 2011 Mac mini models. Lifetime Warranty. Product Details Shipping Weight: 0.8 ounc

www.amazon.com