Heater installs in minutes in non-corrugated lower radiator hose. Great for warming engine on those cold race nights. 120V heater that is thermostatically protected with a maximum heater temperature of 245F / 118C. Three hose diameters to choose from. Hose must have 15 degrees of rise for flow and must have direct access to engine water jacket. Heater weighs about 1Lb.