This RAM bundle includes twelve 4GB modules, providing a total capacity of 48GB. The DDR3 PC3-10600R ECC Reg Server Memory RAM is designed for use with HP/Compaq servers, as well as other enterprise networking and server systems. The voltage of the modules is 1.5V and the frequency is 1333MHz. The RAM features ECC memory, registered modules, and ECC non-registered modules. The form factor is DIMM, with 240 pins and a bus speed of PC3-10600R. This is a great addition to any server system, providing reliable and efficient memory for your business needs.