photocopying machines, computers, computer interface boards, calculators, cash registers, batteries, battery jars, galvanic cells, wires(electric), cables(electric, computer), telephones, facsimile machines, aerials, picture tubes, wafers(silicon), semiconductors, integrated circuits, timers, switches(electric), sockets(electric), plugs(electric), converters(electric), power supplies(electric), uninterrupt power supplies, current rectifiers