Valve Lifters, one of the valve train components, convert the camshaft circular movement in a straight or in an upward or downward movement. This allow the exhaust and intake valves to be opened or closed in the engine.

The Rocker Arms transmitted the movement to the cam, directly to the valve lifters or to the valves. In OHV types, the rocker arm is been driven by the push rods, in OHC types it is been driven directly from the camshaft. The rocker arm's axis of rotation can be pointed in the heart o in an end of the rocker arm. This can be classified according to oscillatory or rolling movements. Wide variety of Moresas lifters and rocker arms designs and technologies support the requirements for different engines.