Intake air is provided by an engine driven Roots blower or turbo-supercharger. The WORX TriVac is a cordless electric leaf blower that doubles as a vacuum. All 645 engines utilize either a Roots blower or a turbocharger for cylinder scavenging. These nozzles are fed with steam directly from the boiler, controlled by the blower valve. Diesel two-strokes often add a Roots blower or piston pump for scavenging. The supercharger must be a 14-71 type Roots blower. An auger in a snow blower or grain elevator is essentially an Archimedes screw. All 567 engines utilize forced induction, with either a Roots blower or a turbocharger. Air is provided for the combustion by an electric blower. Fuel flows into the burner and is burnt with air provided from an air blower. Another mechanical alternative is a camera air blower. It is a mechanically injected two-stroke diesel engine that used a Roots blower. This is usually achieved with a positive displacement blower driven by the crankshaft. Typically, the air is generated by some type of air blower. This is typically done during maintenance with the air blower turned on.