Corsair CMG4GX3M2B1600C7 Dominator GT 4 GB PC3-12800 1600Mhz CAS 7 240-pin Dual Channel DDR3 Memory Kit Each memory module is individually tested to give you Peace of Mind that it Will Not Fail, Guaranteed! 4GB Dominator GT Memory Kit for use with Dual Channel DDR3 AMD Black Edition Processors and AMD BEMP motherboards Perfect upgrade to Compliment Windows 7 and it's great for Gamers who want more speed out of their systems Lifetime Warranty Backed by Corsair  A respected name with a passion for great service and support 4GB 2 x 2GB PC3-12800 1600MHz 240-pin DDR3 Timing: 7-7-7-20 1.65v