Aprilaire 4231 yellow orifices are the tiny nylon components which, accurately meter the flow of water into your humidifier. They allow a specific amount of water to go into the humidifier, unique to your model humidifier. Used in Models 400, 400A, 400M, 500, 500A, 500M, 550, 550A, 558, 560, 560A, 568, 600, 600A, and 600M.
Brand : Aprilaire®
Dimensions : 11/64 in OD
Manufacturer Name : Research Products
Specifications : 3 gph Flow Rate
Suitable For Use With : Model 400, 400A, 400M, 500, 500A, 500M, 550, 550A, 558, 560, 560A, 568, 600, 600A and 600M Humidifier
Type : Replacement


