When you buy Crucial memory, you're buying directly from the largest DRAM manufacturer in America and one of the top three in the world. Crucial Technology is a division of Micron. We have more than 20 years of industry experience, most efficient DRAM manufacturer, and many of the world's leading computer manufacturers use our memory. Crucial brings that same high-quality memory directly to you, the end consumer. / Crucial 4GB DDR3 SDRAM Memory Module - 4 GB (2 x 2 GB) - DDR3 SDRAM - 1066 MHz DDR3-1066/PC3-8500 - 1.35 V - Non-ECC - Unbuffered - 204-pin - SoDIMM / 4 GB (2 x 2 GB) - DDR3 SDRAM - 1066 MHz DDR3-1066/PC3-8500 - 1.35 V - Non-ECC - Unbuffered - 204-pin - SoDIMM