The Eberspaecher Airtronic Air Heaters operate like forced air furnaces utilizing the vehicle’s own fuel and power supply to produce heat without idling the vehicle. Heaters operate quietly and cycle through four output levels to provide the optimum temperatures at all times. The three air heaters (D2, D4, and D5) are suitable for a variety of applications but are especially well suited for cab and sleeper heat in Class 8 trucks, workshop vehicles, and freight compartments. The units are easy to install and maintain, have built-in self-diagnostics, and are EPA verified and CARB compliant.