and transform one socket into a multiple socket. This allows connecting more than one electrical consumer item to one single socket and is mainly used for low power devices (TV sets, table lamps, computers, etc.). They are usually rated at 6 A 250 V, 10 A 250 V, or 16 A 250 V. This is the general rating of the adaptor, and indicates the maximum total load in amps, regardless of the number of sockets used (for example, if a 16 A 250 V adapter has four sockets, it would be fine to plug four different devices into it that each consume 2A as this represents a total load of only 8A, whereas if only two devices were plugged into it that each consumed 10A, the combined 20A load would overload the circuit). In some countries these adaptors are banned and are not available in shops, as they may lead to fires due to overloading them. Adaptors can be made with ceramic, Bakelite, or other plastic bodies. Unusual types Lampholder plug A lampholder plug fits into a light socket in place of a light bulb to connect appliances to lighting circuits. Where a lower rate was applied to electric power used for lighting circuits, lampholder plugs enabled the consumers to reduce their electricity costs. Lampholder plugs are rarely fused. Edison screw lampholder adaptors (for NEMA 1-15 plugs) are still commonly used in the Americas. Soviet adaptor plugs Some appliances sold in the Soviet Union had a flat unearthed plug with an additional pass-through socket on the top, allowing a stacked arrangement of plugs. The usual Soviet apartment of the 1960s had very few sockets, so this design was very useful, but somewhat unsafe; the brass cylinders of the secondary socket were uncovered at the ends (to allow them to be unscrewed easily), recessed by only 3 mm, and provided bad contact because they relied on the secondary plug's bisected expanding pins. The pins of the secondary plug (which lacked insulation sleeves) could not be inserted into the cylindrical sockets completely, leaving a 5 mm gap between the primary and secondary plugs. The adaptors were mostly used for low power appliances (for example, connecting both a table lamp and a radio to a socket). UK Walsall Gauge plug Unlike the standard BS 1363 plugs found in the UK, the earth pin is on a horizontal axis and the live and neutral