Sigma Electric ProConnex AMC-50 BX/MC/Flex Snap-in Connector 1/2-Inch, 50-Pack Terminates aluminum or steel AC, MC and FMC/RWFMC to a 1/2" knockout For aluminum or steel 14/2 - 10/3 AC and MC, and 3/8-in FMC/RWFMC No tools required when connecting to box Zinc-plated steel construction Product is cULus Listed