Stopper for TSG Dip Tubes. For use with Trapped Shower Gullies TSG1, TSG50, TSG52 and TSG2 models only, either sheet flooring or tiled floor versions. Please Note: When after installation the Gully is not going to be used there is a possibility that the water seal will evaporate. The Stopper when inserted into the Dip Tube will prevent foul air entering the building