Metal Brass Knuckles Paperweight Silver Belt Buckle. Our Silver Iron Fist Knuckle duster makes a perfect paperweight in the office or around the house. Screw in the buckle pin and transform this knuckle into a buckle. It features four finger holes with each carrying a rectangle design on the front. It is a Silver color finish with large finger holes measuring approximately 25.78mm in width and 26.74mm in length.