IKN Guitar Bass Knobs Dome Standard Black Steel Metal Pack of 6pcs Dome guitar knobs used for most electric guitar bass with 6mm split shaft pots. Body diameter:approx. 18mm/0.70inch; Length: approx. 18.2mm/0.71inch. Material:metal with plastic inside;Color:black. Hollow Shaft Diameter:approx.6mm/0.24inch. Package include:6 x Dome Knobs.