Used on Fender Precision Bass, Telecaster, etc. The part that fits on the shaft is the type without serrations, and the inner diameter is 6.35mm. It's a side-hole set screw type, and it appears to be inch size. There are minor scratches from use. Please consider this item if you understand that it is an old part. * The description of the condition is subjective, and there may be oversights. * Please consider this item with the understanding that it is a used item being traded between individuals. * Please feel free to ask any questions in the comments section.