A mud motor is described in terms of its stages usually three, lobe ratio and external diameter. Stages are the number of full twists that the stator makes from one end to the other and the lobe ratio is the number of lobes on the stator, to the number of lobes on the rotor (the stator always has one more lobe than the rotor). A higher number of stages or the number of lobes indicates a more powerful motor, capable of producing more torque. A lower number of lobes indicates a reduction in the torque produced but a faster bit rotation speed.