Abstract: A system for determining presence or absence of individual items making up a set of items normally maintained together as a set in a common location, such as a set of golf clubs normally maintained together in a golf bag, utilizes a magnet secured to each respective item. A magnetic field sensor monitors total magnetic field in the common location as an indicator of missing items. Alternately, a sensor can keep track of items removed from and added to the common location as an indicator of missing items. If one or more items are missing, an alarm, such as an audible and/or visual alarm, can be provided in a desired manner, such as when keeping track of gold clubs in a golf bag, when the golf bag is moved.