Abstract: A car plug connectable to an automobile cigarette lighter receptacle including a tip member having a tip terminal, a cylindrical member with the tip member screwed at one end, a base member attached to another end of the cylindrical member, a projection terminal having resilient contacts curved outwardly from the cylindrical member, an inner cylinder securely provided in the cylindrical member, a tubular fuse housed in the inner cylinder, a coil spring inserted between the tubular fuse and the tip terminal, and a metal terminal abutting against the base end of the tubular fuse and having a lead wire connecting portion. The car plug can fit in any size of cigarette lighter receptacles regardless of the diameter without coming off even under severe vibrations and in addition is easy to assemble.