I'm selling this item, which I bought new but never used because I don't have a bass guitar to put it on. It might look cool attached to a black-bodied bass guitar! Attachment dimensions: Upper width: approx. 3cm Lower width: approx. 2.5cm Widest width: approx. 3.4cm Screw hole spacing: Upper approx. 2.35cm, Lower approx. 1.9cm Length: approx. 3.4cm Shaft diameter: approx. 1.36cm Knob width: approx. 3.9cm Measurements are approximate, taken with a measuring tape by an amateur, so please allow for some error. There may be minor scratches from the manufacturing process.