Apparatus for retaining electrical cords of varying thickness within an open top channel. Retaining members are mounted alternately on each of the side walls of the channel each having steps that include a top step adjacent the bottom wall of the channel and a bottom step adjacent the open top of the channel. A service cord having a first thickness can be friction fitted between the top step of each member and the opposite side wall of the channel. Similarly a service cord having a greater thickness can be friction fitted between the bottom step of each member and the opposite side wall of the channel.