8GB Total memory using 2pc of 4GB DDR3, 1600MHz, Non-ECC, CL11, 1R, X8, 1.5V, Unbuffered, DIMM, 240-pin Lifetime warranty for exchange. by Computer Memory Solutions Brand Computer Memory Solutions We don't use Generic modules to avoid incompatibility issues. Guaranteed to work or you get all of your money back including shipping. Compatible with HP/Compaq Workstation Z220 CMT/SFF WILL WORK WITH ONLY Intel Core i3 / Intel C216 Intel Core i5 / Intel C216 Intel Core i7 / Intel C216 Intel Pentium / Intel C216 Intel Xeon / Intel C216 MAX MEMORY 32GB SOCKETS 4