●Zinc Alloy--This guitar tuning key is made of zinc alloy, sturdy and durable, ensuring long‑term use. ●Not Easy To Loosen--The tuned guitar strings of this 12-string acoustic guitar are not easy to loosen. ●Accurately Tune --With these tuning keys, you can tune the guitar strings quickly and accurately. ●Internal Gears--The internal gears of these tuning pegs effectively prevent the screws from slipping. ●Easy To Operate--These zinc alloy tuning keys are compatible with 12‑string guitars and are easy to operate.