Quick-mount, passive, magnetic soundhole pickup. description Moderate output, instant-mount, hum canceling pickup housed in maple cover and double potted. The tone is warm and rich with no 60-cycle hum. Great for strumming and delicate fingerstyle playing. Includes studio-quality 14' cable. complete setup For optimal tone, plug into an acoustic guitar amplifier, P.A., or mixing console. guitars Acoustic guitars with sound holes between 3.85" and 4.10." players Joe Quigley / Lisa Loeb, Mike Dennis, Billy White Acre