This Samsung and Infineon 1Rx8 PC2-4200U-444 DDR2 512Mb RAM kit contains four memory modules with a total capacity of 512 MB. The kit is compatible with computers and tablets, and each module has a capacity of 512 MB. The bus speed is PC2-4200 (DDR2-533) and the memory features include ECC memory, registered, and fully buffered. The brand of the memory module is Samsung, and the form factor is DIMM. The type of memory is DDR2 SDRAM. This RAM kit is ideal for those who need an upgrade for their computer or tablet.