The Aprilaire 4007 is the correct replacement for the following humidifiers:
The Aprilaire 4007 Humidifier Orifice helps to regulate the flow of water into your humidifier. Also known as part number 4007, this humidifier orifice is a white, tiny nylon component that is a unique fit for the Aprilaire 110 and 220 humidifier series. The Aprilaire Humidifier Orifice 4007 could become clogged with mineral deposits and sediments, such as rust and scale. For optimum performance of your Aprilaire Humidifier, replace your orifice annually, based on usage and water quality.
Aprilaire Humidifier Orifice specifications:
Don't forget to clean or replace your inline strainer when you replace your orifice. Disconnect the power and shut off your water supply before servicing. 120 volts could cause serious injury from electrical shock. The Aprilaire brand is also identified by the following spelling variations: April Aire, April Air or Aprilair.