Linergy power distribution blocks are for terminating wires and are designed to NEMA standards. This three pole block has two lug openings on the line (main) side and two lug openings on the load (branch) side. The line side lug is rated to accept one #4 to 350 kcmil copper or aluminum wire. The load side lugs are rated to accept one #4 to 350 kcmil copper or aluminum wire. The lugs are made of aluminum. The lugs are rated for 620 amperes with copper wire and 500 amperes with aluminum wire. The lugs are rated to 600 volts. The housing is made of general purpose phenolic. These Linergy power distribution blocks are UL component recognized and CSA certified.