Offer is for 1 Piece of the highest quality compatible Replacement for The Honeywell HCM-350 and HCM-500. INSTRUCTIONS FOR CHANGING THE UV SANITIZING BULB: CHANGING THE UV BULB1. If the "REPLACE UV BULB" indicator illuminates during normal use, it is time tochange the UV bulb, which is a special 3.5W bulb, EUV-13B.2. Turn the ON-OFF switch to the "OFF" (O) position, unplug it and allow it to cool.3. Remove the water tank from the base of the humidifier.. Place the base of the humidifier over the sink and tilt the unit to remove any remaining water.5. Carefully turn the base of the humidifier over and place it upside down on a flat level surface. You will see a door that is closed with a screw.6. Using a Phillips head screwdriver, carefully turn the screw(s) counterclockwise until the screw(s) separate from the door.7. Open the door. The UV light bulb will be visible.8. Take a replacement 3.5W UV bulb that you purchased from HONEYWELL or another supplier and change the bulb. To prolong the life of the bulb, limit your direct contact with the glass of the bulb by using a cloth or tissue to screw it into place.9. When the new bulb is in place, close the door and replace the screw(s) by using your Phillips head screwdriver and rotating it clockwise until it is just tight. DO NOT OVER TIGHTEN This Premium Quality Replacement lamp is Manufactured by Pro Lighting and is Guaranteed to Meet or Exceed the Original Manufacturers Specifications. The use of the Original Manufacturers Name is for Identification purposes only. The name Honeywell is trademarked and wholly owned by Honeywell . We do not sell or distribute Honeywell Products