The Infineon HYS64V32220GU-7-C2 C3E20328 SDRAM PC133-222-520 is a set of two 256MB DIMM memory modules designed for computers needing a total capacity of 512 MB. These SDR SDRAM modules have a bus speed of PC-133 and feature ECC memory for error correction. With 168 pins per module, this unit is ideal for increasing the memory capacity and performance of a computer system requiring reliable and high-quality RAM components.