Terminology: 2-pin refers to a round, barrel shaped connector 4-pin refers to a trapezoid shaped connector with 4 holes in it
2-wire refers to a non-grounded adapter using a non-grounded line cord You must match the 2-wire adapter to the 2-prong cord
3-wire refers to a grounded adapter using a grounded line cord You must match the 3-wire adapter to the 3-prong cord
Option part number (P/N)
Field replacement unit (FRU) P/N
A/C Adapter (2-pin, 3-wire)
11J8956 - A/C Adapter 76H3516 - US power cord - 3.5 feet long, 3-prong.
56 Watt, Worldwide, has a 2-pin (round connector) tip. The Power Cord ships with it when ordered as a Option. But for the FRU p/n listed here, this is just for the A/C Adapter itself and does not include the Power Cord.