Businesses in the mattresses category sell products designed to provide support and comfort for sleeping. Their ranges may include single, double, king and super king sizes, as well as cot and children's mattresses. Common constructions include open-coil and pocket-sprung mattresses, memory foam, latex and hybrid designs combining springs with foam or other materials. Options can vary in firmness, thickness, materials and features such as washable covers or different comfort layers. Customers may be able to compare mattresses in a showroom or choose from product information online. Staff can explain differences in construction, dimensions and care requirements, and help match a mattress to a bed frame or divan base. Some businesses also supply bed bases, frames, mattress protectors and pillows. Delivery arrangements may include taking the mattress into the home, and some sellers offer installation, removal of an old mattress or a trial period, subject to their terms.