External Battery, fits neatly under the notebook to provide up to 9 hours run time. Includes universal 75W AC adapter Excellent for use on long distance flights. Can be used in a wireless office instead of an ac adapter. Fits neatly under the notebook and eliminates the need for an additional battery. Comes with a range of tips to attach the battery to the notebook via the DC input jack Comes with a universal 75W ac adapter to charge the battery or to use separately