9 Apparatus and instruments for measuring, signalling, monitoring, conducting, commutation, transformation, accumulation, regulating and control of electricity, namely, ammeters, voltmeters, watt meters, phi meters, phase meters, frequency meters, power meters, commutators, converters, transformers, [ relays, sequence meters, temperature indicators, switches, two-way switches, inverters, chronothermostats, telerupters, ] hour meters, [ pulse counters, variators, resistors, stabilised feeders, battery chargers, electric bells, buzzers, alert sirens and transformers, ] current and voltage transformers, [ electric and electronic apparatus for protection against voltage surges and atmospheric discharges, comprising coils, arresters, current reducers, ground-fault interrupters, network analyzers, multimeters, electric dials and panels, shunts, synchronisation units, generators and tachometer indicators, recorders, ] digital indicators