Here's what Taylor say about their Digital Clip On Tuners:

Every guitarist needs a good tuner. The Taylor digital guitar tuner for acoustic and electric guitars conveniently clips to your guitar's headstock, while the easy-to-read display makes quick, precise tuning a breeze for any player.

- Convenient clip-on design lets you tune on the fly
- Clear display is easy to read without extra lighting
- Can be stored on your headstock or a mic stand for quick us