Reversing Valve Material: Aluminum. (The 3-Way Valve Has a Middle Oil Return Function, and the Oil Flows Back to the Fuel Tank When It Does Not Move). No Internal Leakage and External Leakage Will Occur under No-Load and Load Conditions! Use Pressure Within 5mpa. Reversing Valve 3 with Steering Gear, Excavator Loader Can Be Used! The Hydraulic 3-Way Reversing Valve Is Very Flexible and Compact, Which Is Used for Excavators, Loaders, Various Models, Scientific Experiments, Robots, Etc! 1/12 Excavator Can Also Use!