Miller HK50 is a Coolmate 12 portable water-cooling system designed to circulate coolant in a closed loop to keep the welding gun cool during operation. It features a high-pressure pump that delivers coolant at a rate of up to 1.49 gallons per minute, ensuring efficient cooling even at high amperages. The system includes a 12-gallon tank, providing ample capacity for extended welding sessions. It also comes with a three-foot power cord for easy connection to a 115-volt AC power supply.