Japanese standard compliant power strips are for use inside Japan and are used to supply additional outlet receptacles. They are also called "outlet strips". Because the number of outlets fixed to walls, etc., are limited, power strips are often used in offices and construction sites where electrical appliances are in use. Some products have a plug and no cord attached directly to the main unit, but products with extension cords and multiple outlets are more common. Japanese standard compliant power strips are made with materials such as nylon resin that exhibit excellent heat resistance, oil resistance and abrasion resistance. Various types are available and can be selected according to application, including magnet-backed types that can attach to the sides of office desks, types with switches that turn power on and off without having to pull out the cord and types with dust-proofing.