400 watt 120 volt cartridge engine block heater. For GM cars and trucks. The heater is thermostatically controlled to turn on at zero degrees. This meets OE standards. All parts and heater are CSA approved. Protect your vehicle's engine against falling temperatures! Cold temperatures place extraordinary demands on vehicle lubrication, electrical and fuel systems. Kat's heaters offer a wide variety of effective, economical solutions to cold weather maintenance. When air temperatures are less than 20?F, starting a cold engine produces 50 to 100 times more greenhouse gas emissions in the first minute than starting a pre-warmed engine does. Warmed engines also deliver better fuel economy, plus improved oil flow provides better lubrication to the engine during start-up, which reduces wear and increases engine life. What is an Engine Heater? An Engine Heater is an electric heater that heats the engine of a car to give quicker starts in cold weather. They are connected to normal AC power overnight or before driving, via regular power outlets that are fed through a vehicle's grille. This allows easier starting in cold temperatures, by keeping the coolant warm. Heaters are also available for motor oil so as to warm the oil and give the engine lubrication from the beginning of start-up. The rapid heat circulation caused by block heaters also aids the initial vaporization of fuel in the engine; because of this effect, block heaters reduce pollution, as poor fuel vaporization causes much higher emissions.