The Roots type blower is a positive displacement lobe pump which operates by pumping a fluid with a pair of meshing lobes not unlike a set of stretched gears. Fluid is trapped in pockets surrounding the lobes and carried from the intake side to the exhaust. The most common application of the Roots type blower has been as the induction device on two-stroke Diesel engines, such as those produced by Detroit Diesel and Electro-Motive Diesel. Roots type blowers are also used to supercharge Otto cycle engines, with the blower being driven from the engine's crankshaft via a timing or V-belt, a roller chain or a gear train.