The M-frame, P-frame 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 O/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. Copper mechanical lugs are available for use with copper wire only. These lugs can be factory installed by adding an "LC" suffix, to the circuit breaker catalog number for standard copper lugs and "LD" suffix, for high-amp copper lugs (M-frame, P-frame circuit breakers only). This mechanical lug has a rated current of 1200A and material made of aluminum. This lug kit is rated at 500 kcmil. The mechanical lug kit complies to CSA & UL standards.