What is the black rod and why do we have it?

The Black Rod is the official symbol of the Usher of the Black Rod in the Senate. The Black Rod is approximately 1.3 metres long and made of ebony wood. It has a silver crown on the end above the Australian Coat of Arms. The Usher carries the Black Rod while conducting Senate business such as escorting the President of the Senate into and out of the chamber to start and finish each sitting day.