The nest mattress is filled with a thick anti-allergic silicone filler. It islightweight and airy with an optimal thickness to make the nest warmer to use on such surfaces like flooring. It is easy to wash and as it is removable, you will have to wash the nest less often. It can also be used as a changing mat.
I absolutely love it! It’s comfortable for my little on and she sleeps very well. I have two complete nest sets becuase they are just so beautiful! Thank you highly recommending all the time!