Cutting-edge neodymium (a rare earth element) magnets provide excellent string-to-string balance while the pickups active electronics keep the sound pure and clean. These pickups install in minutes, for "plug-and -play" right out of the box. A pre-wired output jack can also be endpin mounted. The pickup may be plugged into an instrument amplifier, sound reinforcement system, recording console or direct box; all with excellent results. For simplicity, the miniature battery mounts conveniently on the underside of the pickup. The low current design of the preamp allows 300 hours use (150 hours for the Rare Earth Blend) between battery changes. All Rare Earth pickups fit in soundholes as small as 3-5/8" (92 mm) diameter. Easy installation with no alteration!