Fits non metallic cable number 6/3 to number 2/3 AWG flex cord .800 to 1.350 inches diameter or SE cable 3 conductor or3 number 1/0 minimum; 3 conductor or 3 number 2/0 maximum. With 1/2" knockout. In a dry location, use to connect nonmetallic sheathed cable to a steel outlet box or other metal enclosure. UL Listed, meets CSA requirements.