The SUN Hydraulics NCFB-LCN is a pilot-to-open check valve with a pilot assist feature, commonly known as a counterbalance valve. It is designed to control motion and provide load holding for hydraulic actuators. This valve allows free flow from the directional valve (port 2) to the actuator (port 1) while blocking flow in the opposite direction until sufficient pilot pressure is applied at port 3. The NCFB-LCN variant features a standard 3:1 pilot ratio and a specific pressure adjustment range, making it suitable for applications requiring stable load control and thermal relief protection in hydraulic circuits.