Models that these upgrades will work for:

HP-Compaq Presario Notebook C500EA, HP-Compaq Presario Notebook C500EU, HP-Compaq Presario Notebook C501NR, HP-Compaq Presario Notebook C502CA, HP-Compaq Presario Notebook C502US, HP-Compaq Presario Notebook C503WM, HP-Compaq Presario Notebook C504EA, HP-Compaq Presario Notebook C504EU, HP-Compaq Presario Notebook C504US, HP-Compaq Presario Notebook C506CA, HP-Compaq Presario Notebook C507US, HP-Compaq Presario Notebook C508US, HP-Compaq Presario Notebook C509NR, HP-Compaq Presario Notebook C518LA, HP-Compaq Presario Notebook C540EA, HP-Compaq Presario Notebook C542EA, HP-Compaq Presario Notebook C552CA, HP-Compaq Presario Notebook C552US, HP-Compaq Presario Notebook C554TU, HP-Compaq Presario Notebook C554US, HP-Compaq Presario Notebook C556CA, HP-Compaq Presario Notebook C561TU, HP-Compaq Presario Notebook C582TU