The Samsung Memory 256MB 1RX16 PC2-4200U-444-12-C3 M378T3354CZ3-CD5 RAM is a set of two DDR2 SDRAM modules with a total capacity of 256 MB each. These DIMM modules feature ECC memory and are designed for high performance in computer systems. With a bus speed of PC2-4200 (DDR2-533) and a manufacturer warranty of no warranty, this RAM is a reliable choice for upgrading your computer's memory capacity. The product is manufactured in Korea, South, by the reputable brand Samsung.