In the production of cast-in-situ concrete diaphragm walls, the use of the correct stop-end-elements plays an enormously important role, especially with regard to watertightness. Especially for wide diaphragms (B 800 mm and larger), the use of stop-end-elements is mandatory, as otherwise the reinforced diaphragm length is greatly reduced (e.g. when using stop-end-pipes). Water tightness between the individual elements is ensured by installing a special rubber seal. LEFFER stop-end-elements are connected with mechanically processed bolt joints, which reliably prevent the ingress of concrete and allow easy assembly and disassembly.