Black Plastic Knuckle Duster - Tophatter's Guns'N'Weapons StoreMade from a durable black ABS plastic material, these black knuckles add punch to your fists. When you put your fingers inside the finger slots and grip tight, you won't have any doubts. With a normal punch, your fingers are just as likely to get hurt as the one you're striking. But with brass knuckles and these plastic knuckles, the hard material will protect your hand while it delivers powerful blows to the jaw of the unworthy. Features: Length: 4.