PNY Optima 4 GB PC3-8500 1066MHz DDR3 Notebook SODIMM Memory MN4096SD3-1066 Memory capacity upgrade provides improved system performance and responsiveness Deliver all the productivity your PC has to offer with PNY Memory Easy installation, Free 24-hour Technical Support, and Lifetime Warranty! Helps prepare your PC for running Windows 7 Compatible with PC3-8500 1066MHz systems. DDR is not compatible with Mac