User interface for external power source, recharger, for an implantable medical device. The housing comprises two fixing grooves that support the terminals. The method further includes determining a risk value for the first order based at least in part on the first product. The magnetic disk device is provided so that a deviation of a center of the voice coil from the magnetization center when the magnetic head is in the innermost position of the data zone is substantially equal to a deviation of the center of the voice coil from the magnetization center when the magnetic head is in the outermost position of the data zone.