A plug is positionable within the recess of the recorder, The plug has a generally trapezoidal shaped interior section with a small rectangular interior region an enlarged exterior region forming a periphery essentially equal in size to the periphery of the recess of the recorder. The interior region is formed with a smaller height and width than that of the exterior region. The interior section also has trapezoidal upper and lower surfaces and trapezoidal side surfaces therebetween. An exterior section is formed as part of the plug. The exterior section has a generally rectangular configuration. The periphery of the exterior member is semicircular in cross section. The interior and exterior member each have a depth.