Description:Material: These electric guitar tuners are made of iron, which is strong, durable and not easy to damage, so you can reuse them for a long time. Spare parts: Iron musical instrument key tuners are suitable for use as a replacement part to replace an old or damaged guitar accessory. Easy installation: Stringed tuning buttons are small and lightweight, which can be installed on electric guitars. Wide Application: This guitar knob holder has a wide range of applications, which can not only improve the sound quality, but also can improve your DIY repair skills. Fit People: The interchangeable accessories of the instrument can be used as a special gift for both professional musicians and beginner guitar players. Specification: Color: Silver, Black, Gold. Material: Iron. Image Size: Width: Approx. 17.5mm / 0.68 inch. Mounting Hole Size: Approx. 3.8-4mm/0.14x0.15inch. Note: There may be several color distortions due to different computer resolutions. There may be a slight error due to different manual measurements. Package Included: 6pcs Guitar Reed Knob Grips .6pcs Mounting Screws .6pcs White Plastic Mounting Sleeves .6pcs Metal Mounting Fittings.