Low loss, low local discharge, low noise, heat dissipation ability, forced air cooling conditions can be 120% of the rated load operation. Good moisture-proof performance, can operate normally under 100% humidity, after shutdown without pre-drying can be put into operation. Safe, inflammable, fireproof, no pollution, can be directly installed in the load center. Equipped with perfect temperature protection and control system, for transformer safe operation to provide reliable guarantee. Maintenance free, easy installation, low overall operation cost. High reliability. According to the operation study of the products that have been put into operation, the reliability of the products has reached the international advanced level.