Our range of 5 In 1 Air Sofa Bed have actually has two chambers. The bottom chamber acts like a mattress box spring to provide support to the upper chamber which acts more like the mattress. This two chamber system also creates significant height for an air mattress and this Intex airbed stands 22 inches off the floor. The top of the mattress is covered with plush waterproof flocking that provides a velvety surface – although a number of consumers indicate that the mattress is made much more comfortable with a mattress topper. The mattress measures 60 inches by 80 inches (queen size airbed) and there is an indentation around the outside of the mattress that allows fitted sheets to fit snugly. It should be pointed out that the mattress dimensions can change depending on the extent to which the mattress is inflated.