... +10%~+25%, -10%~-30% available for presetting.• Output Frequency: 50Hz, 60Hz, adjustable between 45 and 70 Hz, 400Hz ... (Resistor Load); Efficiency: ≥ 85%• Output Instruments: Frequency Indicator, 4-digits RMS digital frequency indicator, resolution 0.1Hz Voltage Meter, 4-digits ... RMS digital voltage meter, resolution 0 ...