The M-frame, P-frame and NS630b-NS1250 circuit breakers have mechanical lugs standard on both ends of the unit-mounted circuit breakers. The M-frame and P-frame I-Line™ circuit breakers have mechanical lugs standard on the ON/OFF end only. These lugs are suitable for use with copper or aluminum wire. Rear connectors, compression lugs and distribution lugs are available for special applications. These lugs are certified to UL, IEC and CSA Standards.