It is small size, light weight, and strong With the functions of Low-frequency protection and voltage slowly established, suppression circuit Suitable for generators,can adjust the voltage slightly to stabilize the output voltage of the generator When the voltage is 4 v / 25 hz,the Voltage be set automatically Model: AVR-20A Phases:single phase Voltage Adjustment Range:210-250 volts min Frequency:50/60HZ Frequency Protection Adj. Range:40-50HZ Output Voltage:0-115 volts-DC at 230 volts Output Current:20A continuous Residual Voltage For Build Up:5 volts minimum Regulation:+/-2% tyhristor Power Output Stage: half wave tyhristor Internal Fusing:10A (fast acting fuse) Operating temp:-10°C (14F) TO 60°C (140°F) Storage temp:-20°C (-4F) TO 80°C (176°F) Maximum humidity:95% non-condensing Dimensions:125 x 68 x 35mm Fixing centers:11 5mm, 2xM6 Material: Metal+PC colour: black Package Contents: 2 x Voltage Regulator Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.