This is a Sonic Research ST-200 Strobe Tuner pedal tuner. It's a highly accurate tuner with a fast response, boasting a precision of ±0.02 cents. True bypass. Operation has been confirmed, and it works without any issues. This listing includes the unit only. 【High-Precision Tuning】 The Sonic Research Turbo Tuner ST-200 is a high-precision tuner that provides accurate pitch adjustment. It's perfect for tuning guitars and basses. 【Multi-Functionality】 With its mode switching function, it supports various instruments. It also features CAL mode and FLAT mode, catering to a wide range of needs. 【Compact Design】 Its compact design makes it easy to carry and is ideal for effect boards. With its simple operation, it can be used immediately. - Brand: Sonic Research - Model: Turbo Tuner ST-200 - Function: Tuner - Output Terminals: OUT - Input Terminals: IN - Power: 9V - Mode Switching: MODE, CAL, POWER ON, FLAT