AddOn 4GB DDR3 SDRAM Memory Module - 4 GB (1 x 4GB) - DDR3-1600/PC3-12800 DDR3 SDRAM - 1600 MHz Dual-rank Memory - CL11 - 1.50 V - Non-ECC - Unbuffered - 240-pin - DIMM - Lifetime Warranty

This Crucial® CT51264BA160B Compatible 4GB DDR3-1600MHz Dual Rank Unbuffered 1.5V 240-pin CL11 UDIMM is 100% guaranteed to be compatible with your system and to work right the first time. Adding additional memory is the best way to increase the performance of your system. All our memory is built to strict JEDEC standards to meet or exceed the Tier 1 OEM's factory requirements. Our products are also guaranteed by federal law to not affect or void OEM warranties.