Klaus uses a unique and distinctive knuckleduster which is strapped to his left arm and usually hidden away until needed in a fight when it drops down with a flick of his arm.
The device is metal, possibly a mix for strength with the addition of a sterling silver cross on the front plate which is traditional European folklore is a known metal to repel and weaken Vampires and other demonic creatures.
![](https://static.wikia.nocookie.net/kekkai-sensen/images/4/48/Chapter_29.jpg)