Brass knuckles are a melee weapon used primarily in hand-to-hand combat. They are fitted and designed to be worn around the knuckles of the human hand. Despite their name, they are often made from other metals, plastics or carbon fibers and not necessarily brass.
Brass knuckles
Brass knuckles carried by Abraham Lincoln's bodyguards during his train ride through Baltimore. Ford's Theatre National Historic Site, 2007
An Apache revolver, a weapon that combines brass knuckles with a firearm and a dagger – Curtius Museum, Liège, 2011
Mark I brass knuckles trench knife
Vajra-musti refers to a "fist-load, knuckleduster-like" weapon and also a form of Indian wrestling in which the weapon is employed. The weapon is sometimes called Indra-musti which means Indra's fist.
Drawing of Indian wrestlers carrying vajra-mushti (1792 A.D.).