Dual-Purpose Beds:

Dual-purpose beds, of which sofa beds and futons are the most common, are distinguished by their ability to 

transform from a sitting surface to a sleeping surface, making them an ideal sleeping accommodation for 

guests. Due to their need to fold and collapse, futons and sofa beds require different types of mattresses with 

unique, flexible construction. Such mattresses are typically sold together with their respective frames to ensure 

that the units function properly.