Upper section for holding standard concrete seating rings and BEGU class A / B / D covers, additional chamber height achieved with concrete rings. If installed in roads, parking areas and comparable hard-surfaced traffic areas for trucks (Class D / exception: in case of rainwater cisterns note relevant load class of the tank) according to RStO, ZTVE-StB and DIN 18196, the upper section must be installed according to the standard road pavement design without additional installation measures. For all other installation situations, i.e. not in accordance with standard road pavement design, a reinforced support slab is necessary to concrete the upper section. The exact design of the concrete slab must be calculated structurally according to the circumstances on site. A standard formwork and reinforcement drawing can be provided. An embedded step (art. no. 860109) must be installed, or an additional access step in the area of the taper section, if the allowable difference between the top of the chamber cover and the first step is exceeded.