Bartolini Acoustic Soundhole Pickup; Soundhole pickup for acoustic guitar, great natural sound, easy to install, stacked coil, hum-killing, magnetic circuit: carbon steel, brass, copper, ceramic blade magnets (ferrite), focused aperture, B-string mass compensation, DC resistance 2.8 kOhm, resonant frequency 9.2 kHz, 55 mm / 2.17" max. sensing width, 3m / 10 ft, 2-conductor, shielded coaxial cable, 6.35 mm / 1/4" plug, passive, black cover, dimensions (L x W x H) 69.9 x 17.5 x 22.6 mm / 2.75" x 0.69" x 0.88" (height incl. cable), fits 89 to 114 mm / 3.5" to 4.5" soundholes (bridge side), Due to the manufacturing process, the plastic housings of Bartolini pickups may show minor processing or handling marks. The cable ends of some pickups may also be pre-soldered. These characteristics do not constitute grounds for complaint or reason for return