13 + 1 FILE: This guitar sanding tool has 13 round files and 1 flat file, 13 different dimension round files for polishing the string slots, enough to meet your different needs, suitable for polishing most stringed instruments. EASY TO USE: The round files for polishing the string slots, and it makes the string slot very smooth. The flat file for burnishing the nut and bridge. There will be no noise and always even vibration in filing. POCKET SIZE: This multifunctional guitar sanding tool can be folded, the size is 7.5 x 2.8 x 1.3cm / 3 x 1.1 x 0.5 inch, compact and small, easy to carry and store, very convenient and practical. WIDELY USED: Almost suitable for strings of any specification between 008-058. This file tool is universal for string instruments, guitar, mandolin, bass,ukelele and banjo etc. SERVICE: If you have any questions about this guitar sanding tool kit, please feel free to contact us by email, and we will serve you wholeheartedly before and after sales.