Barcus Berry 1455-3 Acoustic Guitar Pickup"Insider" Piezo Transducer with Fas-Jac The choice whenever accurate reproduction of the natural sound is required for either reinforcement or direct feed recording application. Easily mounted to the inside of any acoustic instrument. Fully shielded against hum and retains the natural sound of the instrument, free of color or added tone. Furnished with Fas-Jac 1/4-Inchstrap button mono jack. Ideal for acoustic guitar and classical guitar.