Eagle's Splendor Knuckles

The Eagle's Splendor Knuckles were brass knuckles obtained by Jacob and Evie Frye during the nineteenth century. These brass knuckles, shaped like an eagle, were the strongest of their kind. The Frye twins acquired this weapon after killing Lilla Graves and freeing Westminster from Blighter control.

Reference

 * Assassin's Creed: Syndicate