The Shadow SH 340 is a NanoMAG sound hole mount humbucker pickup for steel string acoustic guitar. NanoMAG pickups are low-impedance active mini-humbuckers made with Samarium Cobalt magnets. These innovative Shadow pickups are balanced for both acoustic and electric guitar strings and have a much larger frequency range than your typical midrange-heavy humbucker. This easy-to-install and height-adjustable pickup can be rotated inside your guitar's soundhole to alter tonal response.