1.MC connector,..can also be used w/ AC cable
2.AC/MC "snap-in" connector..no lock nut
3."Flex" connector..for Greenfield ..3/4" and above..
4.Steel AC connector,to be used only on STEEL AC cable.
5.Set screw type EMT connector
6.Duplex AC/MC "snap-in" connector
7.Inside thread Greenfield connector,..seen on lighting whips and in recessed lighting whips...


.."if it ain't fixed,don't break it...call a Licensed Electrician"