Businesses involved in electric items manufacture design, produce and assemble products that use or distribute electrical power. Their output can range from household appliances, lighting equipment and small electronic devices to wiring accessories, switches, cables, control panels, motors and other electrical components used in homes, commercial buildings and industry. Some manufacturers make complete products, while others supply parts or subassemblies to other businesses. Typical services include product design and development, sourcing materials, machining or moulding components, circuit-board production, wiring, assembly and quality testing. Manufacturers may also provide product customisation, technical documentation, packaging and support with production runs. Testing can include checks on electrical performance, insulation, durability and safety.