These mining circuit breakers, originally manufactured by Eaton Cutler-Hammer, may have been purchased either directly from a third party or through a mining supply company. There is evidence that some of these circuit breakers have been modified by a third party rebuilder with knock-off 600 volt and 1,000 volt covers, according to the agency. The covers are of unknown construction and were not manufactured by Eaton. The labeling affixed to the breakers was also reproduced by the third party rebuilder in an effort to make the circuit breakers look new and legitimate.