The 412440-S is a low-cost, pocket sized calibration source checker for simulating current loops and providing a quick and easy way for checking calibration of meters or controllers. Sources three current levels: 4mA, 12mA, and 20mA. Bright red LEDs indicate simulation output and battery status. Overload indication when load exceeds 240ohms. Comes complete with 9V battery, case, and calibration cable terminated with subminiature and spade lug connector.