When the tank or gearbox is ventilated, the system absorbs air with a water mist. Temperature fluctuations cause water mist to condense, which can accelerate oil oxidation or emulsification, resulting in damage to metal parts due to poor lubrication. The function of the dehumidifying air filter is that the air is first passed through the desiccant, and then the air flows through a 3 micron air filter, which removes solid pollution particles from the air. When moisture is absorbed and the oxidation process is reduced, the oil and machine life will be greatly extended. In addition, desiccant can be used in conjunction with corrosion inhibitors to absorb moisture and release corrosion inhibitors to protect machinery and slow corrosion. Products with breathing valves can open the breathing valve when the equipment needs to be ventilated, so as to avoid the rapid deterioration of the desiccant in long-term contact with the environment, and effectively extend the service life.