This is a three pin mini-XLR connection, the male part in the left earcup, the female one on the cable. Pressing the small button on the female plug unlocks the connection. The pin assignment is as follows: (3) - left hot, (2) - right hot, (1) - common return. The other end of the cable is equipped with a stereo minijack (1/8") with screwable 1/4" adapter.