Patriot Viper II Series 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model PV234G1600LLK Extreme Performance PC3-10666 (1333MHz) Low Latency (7-7-7-20)-XMP Ready 100% Tested and Verified Tested on Intel P35, P45, X38 and X48 Chipsets Lifetime Warranty