The Panasonic ESE-20C321 is a three-phase dual-element proportional-integral-derivative (PID) temperature control device. It is equipped with a slotted sensor and is suitable for use in applications that require accurate temperature control, such as in HVAC systems. The device has LED status indicators, a digital LCD, and a digital keypad for programming the settings. It has an adjustable proportional band selection, adjustable deadband selection, and a positive or negative temperature slope selection. It also has automatic recovery, over temperature protection and manual reset. The ESE-20C321 is housed in a DIN-rail compatible aluminum enclosure for easy installation.