Guitar essentials: the guitar saddle file set is used for shaping string grooves, helping to smooth contact points on strings for improved performance. Flat files are ideal for polishing nuts and bridges. Grinding needle size: this guitar saddle file set includes 13 different diameters: 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.05 mm, 1.1 mm, 1.2 mm, 1.4 mm, and 1.6 mm, suitable for various stringed instrument needs. High-quality material: the guitar bridge saddle file set is made entirely of stainless steel, offering smooth operation, durability, resistance to deformation, and long-lasting use. Easy to carry: the set features a compact, organized case with a hole for convenient storage and portability. Keeps files secure and accessible when needed. Wide application: compatible with various stringed instruments including guitars, ukuleles, and basses. A practical tool set for musicians, music teachers, and music enthusiasts.