Special Attention Items Our pet stairs is packed in a vacuum compression package, and the package needs to be opened before use to allow the sponge to contact with the air fully. After about 36 hours, the sponge can fully rebound. Remember to install the cloth cover after fully rebounding, otherwise it will be easily deformed after installation. Product Information Dog ramps for small dogs has a soft and comfortable high-density sponge, a machine washable soft cover. Easy to Disassemble & Clean Through the zipper design, dog step machine-washable soft cover is easy to remove,the foam insert can be spot cleaned or light vacuumed. Upgraded Design Compared with other foam dog stairs, our dog stairs & steps that is made of high-density sponge can bear around 60 pounds.