Aprilaire 4837 Repair Kit The Aprilaire 4837 maintenance kit is designed specifically for your Aprilaire 560 and 568 humidifier and includes all the supplies you need to maintain your Aprilaire humidifier each year Aprilaire suggests replacing the 4837 maintenance kit before every humidification season, or every 12 months The Aprilaire 4837 maintenance kit is designed to keep your Aprilaire 560, 560a and 568 humidifier operating like new!