CF-AA1623AM AC Adapter for Toughbook R1, 18, T1-2-3-4-5, W2-3-4-5, Y2-4 and 08.  This is the exact same adapter that came with your Toughbook directly from Panasonic not a third party replacement adapter.

Keep an extra adapter at the office or your house or use it to travel with you while keeping one at home.