1,CE approval 2,professional meter manufacture 3,ISO9001,IS014001 4,export to Europ,Africa,Asia double reeds frequency meter Specification:Voltage:50V 100V 220V 380V 440V 415VFrequency:45-55HZ 45-65HZ 55-65HZ 47-53HZ 57-63HZThis vibrating reed frequency meter with two rows of horizontally arranged reeds for connection to one main voltage ,Vertical arrangements on requestCasings: the casings and ...