The present invention relates to a cabinet for containing and holding telecommunications apparatus coupled to telephone field cables. The cabinet includes a cabinet housing, at least one cable entrance port through the cabinet housing to allow cables to enter the cabinet and a cable entrance seal positionable around the cable and securable to the cabinet housing for sealing all openings between the cable and periphery of the cable entrance port. In particular, the cable entrance seal is a rigid collar capable of supporting a moisture-blocking material snugly around the cable positioned therein and is attachable to the cabinet by a twist and lock securing means. Furthermore, the rigid collar may be bifurcated into two sections to facilitate positioning of the collar around a cable when the cable has no free-ends available for the collar to be slid over. As disclosed herein, the moisture-blocking material may be a foam block comprising a plurality of concentric split rings registering with each other so that a split opening common to all of the rings extends radially from the periphery of the moisture-blocking material to its center.