The AT24CSW0x family are general-purpose I²C-compatible memory devices that feature 1Kb, 2Kb, 4Kb or 8Kb of EEPROM memory. They also contain a 256-bit Security Register that houses a pre-programmed, read-only, 128-bit serial number. The remainder of the Security Register can be programmed by the user and subsequently be made read-only. The new memories are ramping into production now. (AT24CSW02 data sheet, AT24CSW08 data sheet).