HP 512MB DDR-266MHz PC2100 non-ECC Unbuffered CL2 200-Pin SoDimm Memory Module (Q7723-60001 Q7723AX). This is a seller refurbished part in great working condition. May show signs of cosmetic wear but this should not interfer with the effectiveness of the product. Taken from a working environment. for Color LaserJet 3000/4200/5550 Series Printers