YINETTECH 12Pcs Guitar Tuning Key Buttons Machine Knobs for Acoustic 4x3.8mm/17x12.8mm Black

Designed specifically for all types of folk guitars, it perfectly replaces the original tuning knobs and improves pitch control accuracy. The knob size is 17 × 12.8 mm, the tuning shaft hole size is 4 × 3.8 mm, and it fits the tuning rod tightly. Simple and beautiful square design, comfortable in hand, easy to adjust pitch quickly. Compact design, easy to install with screws, no additional tools or professional skills required, suitable for DIY and professional repairs. Contains 12 pcs square knob, 12 pcs screws, 12 pcs black washers, 12 pcs white washers to meet the tuning needs of acoustic guitar.