There are 2 types of guitars which use two different types of stringsSteel stringed guitars have Slimmer necks and Nylon have wider necksWhich one do you use? steel string For Neck Widths Of 41mm to 46mm& Some Smaller Nylon String Guitars nylon string For Neck Widths Of 47mm to 52mmUnsure? Measure Neck Width At Nut