Aluminum knobs are for sound equipments or rotary potentiometer, The knobs have a knurled finish around their circumference. These knobs do not have a plastic insert; they are CNC machined from one piece of solid aluminum, with a durable anodized surface finish.
Material: aluminum ;Color: Black .
Total Size: 20 x 17 mm / 1" x 0. 67" (d*h); inner Hole diameter: 6mm / 15/64"