Air sofa is completely contained in a machine washable cover with easy grip zippers that provides stability and helps prevent movement when you pet gets on and off. Built to last with no sagging and increased durability compared to foam beds, and is lightweight which is great for travel, camping, etc. A separate air bladder holds air for both the bolster and the flat base of the bed. Assembly is a snap with the provided air pump. Bed firmness can be adjusted by the amount of air pumped into the quilted sleeping area.