TOPSEAL Plus® manhole system impresses from the planning stage right through to the construction site. It meets the requirements of the DIN 4034-1 and EN 1917 standards as well as the increased demands for safety and statics in the market for prefabricated manhole components. The core of the system, which has been innovative for 20 years, is a one-piece, factory-integrated seal with circumferential load compensation by means of a non-resilient sand bed, firmly integrated into the concrete body.