Appleton and O‑Z/Gedney offer SPEED‑LOCK Connectors. The steel box connectors are used in 1/2" and 3/4" knockouts to ground and secure MC, AC and flexible metal conduit to boxes and enclosures. The snap connectors are used in 1/2" knockouts to ground and secure steel or aluminum AC, MC, MCI, MCI‑A, HFC‑MCI, FMC and RWFMC flexible metal conduit to boxes and enclosures in dry locations.