At HeroPetBeds.com, we offer an open cell, polyurethane foam as an option on all of our pet beds. Polyurethane foam has unique properties that make it both mold and mildew resistant. Our foam is designed so it will not flatten out or degrade over time. Most pet beds that are commercially available use a low grade, thin foam unlike HeroPetBeds.com which uses furniture grade foam that weighs 1.8lbs./FT3 (cubic foot). This high grade foam is used throughout the furniture industry due to is durability and comfort. We believe that our furry friends deserve to be as comfortable as us, which is why we also wrap all of our foam pet beds with 100% thermal bonded polyester batting which creates a plush loft and makes our pet beds even more comfortable.