Handmade brass knuckle

Brass knuckles are a type of hand weapon or knuckleduster that consists of a piece of metal shaped to fit around the knuckles, typically with finger holes for a secure grip. They are often used as a weapon for self-defense or in altercations, but their possession and use can be illegal in many places due to the potential for harm. It's important to be aware of your local laws and regulations regarding such items. 

"Knuckles" can refer to two different things:

1. **Knuckles on the Hand:** These are the joints at the base of each finger, where the fingers meet the hand. They are also known as metacarpophalangeal joints. Knuckles are important for hand mobility and grip.

2. **Brass Knuckles:** Brass knuckles, also known as knuckle dusters, knucks, or knuckle busters, are a type of weapon designed to be worn around the knuckles. They are typically made of metal (not necessarily brass) and are used for self-defense or as offensive weapons. However, they are illegal in many places due to their potential for harm.