Diesel generator water jacket heater engine coolant preheating thermostat 4061041. Directly replace the old or broken one, easy to install. easy to use and install due to the small size, light weight and simple structure. Optimizes the vehicle's cold-start coolant circulation logic, effectively shortening engine warm-up time, rapidly increasing engine temperature, and significantly improving start-up and operation in low-temperature environments. In summer, it can precisely block the heating duct circulation path, preventing residual heat from penetrating the engine compartment and helping to improve the vehicle's air conditioning cooling effect, thus comprehensively optimizing the driving and riding comfort experience.