At this price I do not understand how a defective circuit breaker is sent to the customer. One of the poles does not conduct electricity. I had to climb and drive 40 miles to find another for an urgent project. Since this thing costs the same as a laptop, you'd think the quality control process would sort out any defective products. At least Revain was quick with the return and refund process. If you purchase this product, be sure to test it with a multimeter before installing.