This is a set of two knurled, glossy black knobs for knurled-shaft 6mm potentiometers. These knobs make a great, inexpensive finishing touch for your special build, and provide a nice "premium" look that plastic knobs just can't give. These knobs are metal with a plastic insert that fits over the pot shaft.
Here are the sizes of these knobs:
Outside Diameter: 9/16" (.56" / 14.22mm)
Height: (9/16" (.56" / 14.22mm)
Inside (Shaft) Diameter: 1/4" / 6mm