There are many different ways to tune your guitar. You could use a tuner or, what is much better, tune your guitar by ear. All you need is your guitar, a correct A, your ears and the willingness to listen carefully.
This tuning fork made of steel with a round shape vibrates 440 times per second and thus projects a pure A 440 Hz. It is mounted on a wooden resonance case to increase the volume and tune easy by ear. Comes with striker.
The easiest, fastest and most accurate tuner are your ears!