The drainage system offers the simplest installation method: just plug the system parts together and align them. The concept is characterized by its optimized waste-water volume flow and its five design elements: the 30° markings and stop ring make it possible to align the fittings quickly and determine the insertion depth. The four laterally extending grasping ribs serve to create a good surface feel when plugging the fittings together. The flanged walls have a sound-insulating effect. The flattened ridge along the direction of flow integrates the product description and company logo and unifies all the design elements in a single unit.