Line cord strain relief attachment for telepone test set

A strain relief attachment for attaching a telephone communication cord to a telephone test set has a line cord strain relief element, a grooved neck end of which is insertable through a tunnel through an end of the test set to a strain relief engagement cavity adjacent to a battery compartment of the test set and accessible by a battery door. The strain relief element includes a bore through which the line cord extends and a flange configured to conform with an external surface of the test set adjacent to the tunnel. The strain relief element engagement cavity is connected by a line cord passageway to the battery compartment. A wedge-shaped line cord retention plug is inserted into the strain relief engagement cavity, engaging the grooved neck of the line cord strain relief element and a wall surface of the strain relief engagement cavity. As the wedge-shaped line cord retention plug is inserted into the cavity, it draws the line cord strain relief element into the test set, urging the flange of the line cord strain relief element into sealing engagement with the external surface of the test set.