4GB Winchip PC5300 667 MHz 2x 2GB Notebook Memory for Apple MacBook & Mac Pro Capacity & Type:4GB 2x 2 GB SDRAM-DDR 2 for Notebook PCs Memory Configuration: non-ECC, Unbuffered SODIMM Operating attributes: 667MHz, PC-5300 or PC5300 at CAS Latency CL-5 Physical: 200 Gold-plated pins, Low Density (High Compatibility) ICs, Multi-Layered PCBs