This is the TU-12, a digital chromatic tuner. It's a device for tuning instruments and adjusting their scales. The internal battery was not included, so I confirmed its operation up to the point of powering it on with an external power source, but I haven't been able to confirm all functions. Please be aware of this. - Model: TU-12 - Type: Chromatic Tuner - Accessories: Instruction manual - Color: Black Thank you for looking. ※Note※ I may be slow to respond when traveling. I will state the situation in my profile, so please check there if you are in a hurry.