Genuine Aprilaire Humidifier Maintenance Kit 4839 - for Models 600, 600A, and 600M For Aprilaire Humidifiers 600, 600A, and 600M Genuine Aprilaire replacement parts made by Aprilaire in Wisconsin Made specifically for Aprilaire humidifiers Includes: Water Panel 35, Scale Control Insert 4330, Water Distribution Tray 4331, Feed Tube and Compression Sleeve 4335, Orifice 4231, Drain Spud 4223, Inline Strainer 4004, and Owners Manual