Extremely high reliability, very low MTTR and high MTBF figures. Low price, excellent after-sale service and long time warranty ... instantaneously,no need to watch by man.4 Stable voltage,working reliably,easy for maintenance.5 Long lifespan which ... work normally,150%- compulsive protection in 1 second.3Protection:low-voltage,over-voltage,over-load,phase-shortage,short circuit,over-heat,accumulator ...