This Cisco MEM2821-512U1024D compatible 1GB DRAM 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 the Magnuson-Moss Warranty Act to not affect or void OEM warranties.