Improves job site productivity when installing metal clad, MCI-A (such as Southwire's MCAP and MC-PCS) or armored cable to a steel box or enclosure. No tools are needed for installation. Simply insert cable or conduit into the connector and install into knockout. The Quick-Lok Pro family of connectors are removable. 3/8 IN, 1/2 IN Knockout, 0.395-0.638 IN Openings, Steel, Zinc Plated.