The GY-681-4 PVC pneumatic control block is designed for fuel tankers with one to seven compartments and serves as a central component of the vehicle’s pneumatic control system. The pneumatic control block provides centralized control of emergency shut-off valves, bottom valves, vapor recovery valves, and other air-operated components. Operators can control each compartment independently or activate an emergency shut-off across the tanker, making the unit suitable for the safety control systems of refined-fuel transport vehicles.