The Samsung 1GB DDR1 DDR-266 PC-2100 Unbuffered 184-Pin DIMM RTG-1GB-DDR-266-RF is a single module of DDR1 SDRAM memory, specifically designed for computers that require a total capacity of 1GB. With a form factor of DIMM and a bus speed of PC-2100 (DDR-266), this memory module offers reliable performance and compatibility with a variety of systems. The unbuffered design ensures lower latency and improved stability, making it a solid choice for upgrading or replacing existing memory modules in your computer.