5100% Satisfaction Guarantee: : is committed to bringing a pleasant shopping experience to all customers. If anything happens to the product, please feel free to contact us. We solve the problem for you 24 hours a day, you can replace the defective product or return it for a refund within 30 days.1 What You Get : : 6 x guitar tuners (3 left + 3 right) comes with ferrules, screws and bushings. Suitable for 0.39 inch / 10mm standard head hole. The content of the package is rich enough to meet your needs.2 High-quality Material : : The guitar tuner is made of high-standard metal, which is not only sturdy and durable, high stability, but also has anti-corrosion performance. Frequent use will not cause wear and tear. It is an essential accessory for music lovers.4 Multi-purpose : : The guitar locking tuner is very practical, applicable to a wide range, and is deeply loved by music lovers. For example, electric guitars, classical guitars, acoustic guitars, steel string guitars. Look forward to accessories to accompany your instrument every day.3 Powerful Functions : : The guitar tuning heads are not only easy to install, but also have adjustable functions. After adjustment, the guitar's sound is stable. After our test, the guitar strings can be adjusted accurately and without string looseness. It is a very cost-effective music accessory.