The Seymour Duncan SA-6 combines a high-quality hum-canceling magnetic stack pickup with an omni-directional condenser mic that includes volume controls. This design captures not only the string vibrations but the natural acoustic resonance generated by the body of the guitar for a very rich, yet clear tone. This unit is in good working order and includes everything shown in the photos. Missing are one adhesive velcro strip for attaching the battery holder to the inside of the guitar and the "N" battery clips, which are not necessary for a standard installation. Fits into guitars with soundholes from 3.75” to 4.2”. Powered by one 9 volt battery.