This is a replacement part for the square filter pads that comes with the 24 Eggs incubator from Ali Express. https://a.aliexpress.com/_EGL3KXK

It normally uses 5 filter pads that is quite difficult to come by. I have designed this replacement to go into the slots of the water tank and they hold a small piece of round filter stick 8 mm in diameter. They are easy to find and also cheaper and you can cut it to appropriate length. 
 

The 5 pieces is the amount needs to go into the water tank and it amounts to about 12 g of filament. It's a quick print and works like a charm. 

Credit goes to my lovely wife who had the idea and helped designing it to fit perfectly. 

Printing instructions:
Please make sure to use a brim and your build plate has good adhesion. It will print without other support standing.