The GAT offers outstanding long term battery operation by activating itself automatically for short periods of time (5 minutes) at preprogrammed intervals (usually daily, weekly, or monthly). This allows the GAT to be located at the first interval after the asset is lost or stolen while conserving battery power at all other times. Battery life is dependant upon selected interval. Optional extended life battery pack and waterproof case is also available to enhance performance time. In addition, optional external sensors such as vibration, magnetic, temperature, pressure, or humidity are available for optimal battery life up to 3 years. Examples of sensors are, Magnetic (#588131), Pressure (#18400061), Humidity (#1860230), Vibration (#MSR320). All sensors can be found at www.jameco.com