This is a 24 volt, AC-powered button that turns your humidifier’s water on and off. A sieve screen is already built into the valve. This screen filters the water before it goes through the valve, catching things like sand and dirt that could get stuck otherwise. About every ten years, or more often if it breaks and gets stuck open or closed, this valve needs to be changed. Don’t pay attention to the version, opening size, part number, or power written on your old valve. The way this item is made has changed a lot, so the power and your unit’s model number are what matter.