Kingston 1GB PC2-4200 DDR2-533 UNBUFFERED NON ECC CL4 240 PIN 1.8V Dimm MEMORY MODULE( KTH-XW4200AN/1G 9905431-017.A00LF). This is a seller refurbished part in great working condition. May show signs of cosmetic wear but this should not interfere with the effectiveness of the product. Taken from a working environment.