THQL series circuit breaker is for overload & short circuit protection which used in residential and industrial distribution system. Characteristics: Copper stabs, tin-plated for corrosion resistance, make the connection reliable and permanent; Heat-resistant thermoset cases and covers add stability and structural rigidity; Trip are easy to spot because handles trip to the center position; The dedicated calibration screw is cemented(not simply papered over) to prevent shifting, the result is stable calibration for optimum trip performance. The item is installed into plug-in type mounting base.