Total 4GB 2 X 2GB Kit PC2-5300F 667MHz DDR2 ECC 240-pin Fully Buffered DIMM FB DIMM Server Low Power Memory. JEDEC industry standard. Parts Quick Equivalent to HP Part Numbers: 397413-B21, 442823-B21, 461828-B21, EM161AA (2pcs). BEWARE! DO NOT BUY FROM OTHER VENDORS WHO CLAIM THEY ARE SELLING PARTS-QUICKBRAND. OUR WARRANTY IS ONLY FOR ITEMS PURCHASED DIRECTLY FROM PARTS-QUICK. ALLPRODUCTS BRANDED AS PARTS-QUICK ARE TO BE SOLD SOLELY BY PARTS-QUICK. PARTS-QUICK DOESNOT AUTHORIZE THE USE OF IT"S BRANDED PRODUCTS TO OTHER SELLERS. Compatible with:HP StorageWorks 400r All-in-one