This HP® B1S53AA compatible 4GB DDR3-1600MHz Dual Rank Unbuffered 1.5V 240-pin CL11 UDIMM is 100% guaranteed to be compatible with your system and to work right the first time. Adding additional memory is the best way to increase the performance of your system. All our memory is built to strict JEDEC standards to meet or exceed the Tier 1 OEM's factory requirements. Our products are also guaranteed by federal law to not affect or void OEM warranties.

• DIMM 4 GB of memory to refine your computer's performance
• DDR3 SDRAM interface multiplexes 2-bit data from memory cell and I/O buses to minimize processor idle time and enhance your computer's performance
• Up to 1600 MHz speed with Unbuffered signal for smooth computer performance