Headphones; Audio headphones; Electric plugs; Electrical adapters; Electrical cables for musical instruments; Electrical plug device enabling connection and disconnection of power and/or control cables; Electrical plugs; Electrical plugs and sockets; Headphones including attached lanyard; Headsets for mobile telephones; Musical instrument adaptors; Converters for electric plugs; Covers for the prongs of electric plugs; Electric cables and wires; Electric wires and cables