The PRO-AGX-312 Under Saddle Transducer Pickup is a ceramic under saddle passive pickup. It is easily installed beneath the bridge saddle. This is their wide format 1/8 inch (3.2mm) It is wider to better work with classical or 12-stringed acoustic guitars. It is a passive transducer and requires no battery. Slight modification is required to mount, but nothing that is visible. Fully shielded against hum and retains the natural sound of the strings free of color or added tone. Furnished with end jack. This is brand new and in the box with all instructions and warranty information. A free Fishman chromatic tuner is included. This is my personal favorite tuner. I love the automatic feature that turns this on when you flip it open and turns off when it is folded down as well as the full color display.