This high-density foam cushion includes 4 pieces. You can choose the appropriate model directly based on the actual size of your furniture. The foam can be cut by yourself, and you can trim it to any size or shape as needed. This can be done without professional tools. When replacing, you don't need to replace the entire set of furniture. Just remove the old and collapsed foam core and replace it with this product to complete the upgrade. The product is packaged in a vacuum compression method to ensure safe and undamaged transportation. After opening the package, the foam will gradually expand and fully restore its original shape and size within 2 to 4 days. Whether it's a sofa cushion, dining chair cushion, car seat, or boat cushion, it can provide a stable and comfortable support experience.