This is a guitar knob I designed; I call it Smiley knob. I love the open shape on this knob, very stylish and original. This guitar knob will work for volume and tone control on your guitar or bass. It will fit any potentiometer up to ¼” diameter. It is designed to self tap with a 6-32 set screw, if the part is ordered in plastic. If the part is made out of metal you may need a 6-32 tap. If you want to modernize the look of your guitar, this is the knob to get. The functionality is not sacrificed over design.