4GB Kit ( 2x 2GB Modules ) DDR2 800 MHz ( PC2-6400 / PC2-6400U ) DDR2 DIMM ( 240-Pin ) Non-ECC UDIMM ( Unbuffered DIMM ) 1.8V - DDR2 Standard Voltage High performance Memory RAM upgrade designed for Desktop PC / Computers Easy to install and compatible for select (not limited to) Acer, Alienware, ASRock, ASUS, Dell, DFI, Fujitsu, Gateway, Gigabyte, HP, HP Compaq, Intel, Lenovo, LG, MSI, Panasonic, QNAP, Samsung, Sony, Supermicro, Synology & Toshiba Models All modules undergo quality assurance testing to ensure dependable and reliable performance Please verify the supported memory (RAM) specifications of your system prior to purchase to ensure compatibility A-Tech provides a Lifetime Warranty for all orders & offers complimentary United States based Tech Support before, during, & after your purchase