Barcus Berry DISQOS Soundboard Transducer for External Mount Ideal for virtually all types and sizes of acoustic stringed instruments equipped with a soundboard, such as steel stringed guitars, dulcimers, and mandolins. Furnished with Barcus Berry exclusive Fas-Jac 1/4-Inch strap button mono jack or 1/4-Inch external mount output jack. Easy to install and provides high sound levels with no feedback. Ideal for mandolin, banjo, classical steel guitar, ukulele, violin, viola, zither, dobro, drum trigger, steel drum, dulcimer, guitarron, kalimba, koto, lute, balalaika, berimbau, sitar, oud.