Tuner Machine Head Buttons, Guitar Tuning Pegs Button Plastic + Metal for Folk Guitars Pearl White Specification: Item Type: Tuner Machine Head Buttons Material: Plastic + Metal Package List: 12 x Tuning knob 12 x Screw 12 x Black Spacer 12 x White Spacer Note: Only approximate size for this tuning knob mounting hole for reference, can not be totally exact.Only the approximate for reference. Customers can be be sure if this mounting hole is too big to install according to this size. But if the mounting hole is too small for you, would be hard to fit in. If so, please enlarge the hole with small file. So that this problem can be saved. Please check all very carefuly before order. Thanks for your cooperation.