Passive, noiseless, magnetic sound hole ‘pop-in’ hum-cancelling pickup for acoustic guitar that uses Stack technology and delivers warm, full-bodied acoustic tone, ideal for all types of guitar playing. Hum-cancelling design delivers more compressed sound than single-coil version, slim body profile, double wax-potting and epoxy surround make it highly resistant to feedback. Pickup is housed in hand-polished rock-maple housing and can be instantly mounted into the sound hole, without necessity for modification of the guitar, fitting all standard sound holes (diameter 94 to 100 mm). 4.2 m long low capacitance, studio quality cable is included. NOTE: This is pickup will not work with nylon stringed instruments.