A blockage remover. Simple to use and effective. This force cup used water pressure to remove blockages within pipes and drains. Powerful and effective blockage removal Used water pressure. Suitable for domestic pipes and drains. Creates water pressure to remove blockage. Simple to use. 4" diameter cup. The Rothenberger 4" force cup plunger is a powerful and effective tool for the removal of domestic blockages. The force cup uses water pressure to remove blockages that can occur in pipes and drains. Simple and effective to use.