MC4 connector
The MC4 system consists of a plug and socket design. The metal contacts of the plugs and sockets are inside plastic insulators; the plug''s metal contact is inside a cylindrical insulator that looks like a socket, and the socket metal contact is inside a square probe that appears as a plug. The socket has two plastic locking tabs that have to be pressed toward the central probe slightly to insert into holes in the front of the plug connector. When the two are pushed together, the fingers slide down the holes until they reac