A manifold-mounted manual lever-operated hydraulic directional control valve is a type of valve that is installed on a hydraulic system's manifold or subplate, typically designated by sizes like CETOP D03, D05, or D08. These valves are controlled manually using a lever or handle and are responsible for directing the flow of hydraulic fluid within the system. They play a crucial role in controlling the movement of hydraulic actuators, such as cylinders or motors, by redirecting the flow of pressurized fluid to different parts of the system. This type of valve is commonly used in various industrial applications where precise control over hydraulic machinery is required.