Ensures a calm inflow of rainwater within the rainwater storage tank. Fine dirt particles remaining in the water slowly sink to the bottom. A sediment layer forms, which has a proven positive influence on the stored rainwater, because rainwater storage tanks with a sediment layer have clearer water. The calmed inflow of water prevents this sediment layer from being stirred up, and at the same time oxygen is added to the lower part of the stored water. Ideal for use in large systems. The 3P Calmed Inlet can be connected with a plastic pipe DN 250.