The difference between our slab of slab of foam and convoluted foam that you see for sale is air. Convoluted foam was invented partially to save foam and sell air. A 2 inch piece of convoluted foam may actually really be 1 inch of foam. Our foam slabs are foam, not fancy air. Sometimes a mattress needs a slab of foam to either make it more comfortable or to extend the life of the mattress. Many times, a mattress can be an odd size which will make the mattress expensive or difficult to find or both. We have slabs of foam, custom cut to your size mattress. Our foam is high quality, medium density (2.8), which will help give your mattress a medium firm feel.