Aprilaire Maintenance Kit for 550, 550A, & 558

Aprilaire Humidifier Maintenance Kit 4793 includes everything required for your Aprilaire Humidifier 550, 550A and 558 to continue operating at its peak efficiency. Includes: # 10 - Water Panel # 4004 - Inline Strainer # 4231 - Yellow Orifice # 4223 - Drain Spud # 4226 - Water Feed Tube # 4217 - Scale Control Insert # 4218 - Distribution Tray Printed Manual