No tuning, no hand injury of the guitar strings with custom spring tension stud adjustable , the user can adjust the guitar strings according to their own feel arbitrary tightness. And this intelligent guitar's tuning-free function, to achieve the guitar string tension adjustment does not affect the intonation, no need to buy a separate tuner, it is a real gentle guitar does not hurt the fingers! High fidelity CD sound quality:44.1KHZ high sampling frequency and 32-bit sampling accuracy, acoustic guitar and electric guitar tone switch at , while having two kinds of guitar two kinds of guitars, so you can easily perform folk and rock Rolling two classics. Intelligent self-learning system It has a variety of ways to practice grid climbing, five types of fingered scales, eleven types of chord practice, pre-prompts the playing grade by liquid crystal and metronome, intelligent real-time determination of playing right and wrong, real-time display of scale grade chart and playing right and wrong. Wireless bluetooth connection The smart guitar has a built-in bluetooth BLE4.0 data module that can be bluetooth connection to standard midi-enabled APPs, Creating Versatility More than just a guitar, it's a MIDI controller, which means it can playjust about any instrument you can think of, including compatibility with for GARAGEBAND, for SAMPLETANK,for LIVE, and many other applications Power input: DC 5V 1A Battery: 2000mAh Endurance : 8-12 h Colour:Black Material:Metal Package Contents: 1 x Electric Guitar 1 x Charging Cable Only the above package content, other products are not included. Note: Light reflection 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.