“The dishwasher is a fantastic way to make sure hats keep their shapes, Remove the batteries from the battery holder case and replace cover before washing. Put hats on the top rack, head opening down, on a separate wash cycle from dishes because you can’t use dishwasher detergent (many contain bleaching agents). Instead, fill the detergent cup with borax, found in the supermarket laundry aisle. Run a regular cycle without the heated dry option. Pull the cap out and remove the battery holder cover and wipe out any moisture with a paper towel. Leave the battery holder uncovered and place hat over a glass or jar to dry. When dry, replace the batteries making sure the plus side is facing out and install the battery holder cover. You may need to open the Velcro adjustment strap a smidgen the first time you wear the cap after washing but it should stretch back out to its original size.