The GE Q-Line 30 Amp 1 in. Double-Pole Circuit Breaker features tin-plated copper stabs to create reliable, permanent and corrosion-resistant connections. The unit has a dedicated calibration screw that is cemented to help prevent shifting and an attached screw to create a stable calibration for optimum performance. This double-pole circuit breaker has a case that is made of heat-resistant thermo-set for stability and structural integrity.