Ready-to-assemble furniture (RTA), also known as knock-down furniture (KD), flat pack furniture, or kit furniture, is a form of furniture that requires customer assembly. The separate components are packed for sale in cartons which also contain assembly instructions and sometimes hardware. The furniture is generally simple to assemble with basic tools such as screwdrivers, which are also sometimes included. Ready-to-assemble furniture is popular with consumers who wish to save money by assembling the product themselves.