High-elastic rubber pad, enlarge the contact area to prevent the tuner from sliding, compress the instrument while protecting the surface of the instrument from abrasion 360 degree rotation, flexible adjustment, you can move as you want, 360 degree all-round rotation, more convenient to use Power saving function will automatically shut down without a button within 60 seconds, and lock the power Easily learn to tune, simple screen and numbers and letters, meanwhile, the tuning mode is more intuitive Various tunings: twelve equal temperament, guitar, bass, violin, tuning range: A0 (27.5Hz) ~ C8 (4186Hz). Backlight display, can be used in dark environment A4 frequency range: 430 ~ 450 (Hz) Colour:black Material:ABS Size:89 x 53 x 18.5mm Package Contents: 4 * Guitar Tuner Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.