Takamine TRI-AX 2, Magnetic Pickup For Steel-String Guitar, Suitable for the Cool Tube Preamp, Adjustable pole pieces for fine tuning, Resistant to feedback, Passive / active switch, Volume control, 1000 Hours running time with a CR2032 battery, Soundhole size: from 8.9 cm, Includes cable-to-end-pin connection cable (standalone operation)