Features: 1)The products are suitable for frequency of 50/60Hz, rated insulation voltage up to 690-1000V, rated operational current up to 9-400A at rated operational voltage up to 380V under the utilization category AC-3. 2)Used for long-distance making and breaking in circuit, frequently starting and controlling AC motor. 3)The products comply with IEC947-4-1 and GB14048.4.