4GB STICK For HP-Compaq Pro Desktop Series 3515 (Microtower) 4000 (Small Form Factor) 4300 (Small Form Factor) 6000 (All-in-One) 6000 (MicroTower) 6000 (Small Form Factor) 6005 (MicroTower) 6005 (Small Form Factor) 6200 (Microtower) 6200 (Small Form Factor). DIMM DDR3 NON-ECC PC3-10600 1333MHz RAM Memory. Genuine A-Tech Brand. 4GB STICK DIMM DDR3 NON-ECC PC3-10600 1333MHz 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)