The 5ft/1.5m 1 M19 male to 1 pigtail burial cable.  The cable has 2 applications. First, as a termination at the amplifier start of the line.  The pigtail end will connect to most amplifer screw terminals and binding posts. Can also be soldered to any specialty connector, like a Speakon. The second application is for connecting a James Loudspeaker Outdoor Tower speaker to a standard buried cable where a wire nut will be used to connect to the audio line.