COMPATIBLE LAPTOPS INCLUDE: HP Compaq 2000 Series HP Compaq 6000 Series HP Compaq NC Series HP Compaq NW Series HP Compaq NX Series HP Notebook PC 500 Series HP Omnibook 2000 Series HP Omnibook 300 Series HP Omnibook 500 Series HP Omnibook 400 Series HP Omnibook 5000 Series HP Omnibook 500 Series HP Omnibook 800 Series IN ADDITION TO ALL MODELS LISTED IN TITLE Please note the HP Compaq 18.5V 3.5A Adapter is very popular and there is a model with a larger connector (this one) and one with a small connector (we also sell them). Please contact us if you need any assistance in selecting the correct adapter.