Duckhead

A "duckhead" refers to a small corner piece that attaches to a power adapter or "brick", so named because of a vague resemblance to the head of a. These are used to modify such adapters to physically connect with various types of around the world. Apple offers a variety of such "duckheads" in its World Travel Adapter Kit.

History
The Titanium PowerBook G4 and 2nd generation iBook G3 (white) were introduced in 2001 as the first Apple products to come with power adapters that used "duckheads". The "duckhead" form factor has changed little over the years and is physically interchangeable between power adapters for different products. In January 2016, Apple recalled some "duckhead" adapters and redesigned them to reduce the risk of electrical hazard if broken.

Apple products with a "duckhead"

 * Apple Battery Charger
 * Apple MagSafe Power Adapter
 * Apple MagSafe 2 Power Adapter
 * Apple World Travel Adapter Kit
 * Power Adapter Extension Cable
 * USB-C Power Adapter