A molded case circuit breaker having separable main contacts and an operating mechanism utilized to cause the separable main contacts to open and close. A trip unit is provided to actuate the operating mechanism in desirable circumstances. The circuit breaker has external terminals which are connectable with an external load and an external power supply. A collar is used to interconnect the circuit breaker terminals with the load and power supply. The terminal collar in this case is non-symmetrical. The non-symmetrical collar provides two functions: the first function is that the path of electrical continently between adjacent collars is enlarged for higher voltage applications because of the non-symmetrical nature of each collar; secondly, the circuit breaker case has a seat therein which has the same cross-section as the non-symmetrical collar, so that the collar can only be inserted therein in one cross-sectional orientation.