8GB KIT 2 x 4GB For HP-Compaq Pro Desktop Series 6300 6305 HPDesk 600 G1 HPDesk DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine A-Tech Brand 8GB KIT (2 x 4GB) DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For HP-Compaq Pro Desktop Series. (See Compatibility List Below)