Description:Neck Adjustment Nut Bridge Files13 x Round Files (For String Slot Depth)1 x Flat File (For Nut And Bridge Height)Suitable for acoustic guitar and electric guitar, almost suitable for strings of any specification between 008-058 corresponding to string slots. The round files are not very sharp, they need some time to put them together, but the string slots will be very smooth, there will be no noise and no uneven vibrations. Specification: Material: Stainless Steel Color: Blue Size Chart: Approx. 28.5x7 2mm/1.12x2.83inch. Package Included: 1 Set Nut for Neck Adjustment/Bridge File Note: Can use for bridge bones and plastic guitar, can not use for guitar bridge matel.