Upper section with clamping ring for chamber systems LW 1000/800/600 suitable for cover plates resistant to surface water, class A/B or D, locked, continuously height-adjustable by 500 mm (Comfort chamber system) or 450 mm (standard chamber system). If installed in roads, parking areas and comparable hard-surfaced traffic areas for trucks (Class D), the upper section must be underlaid on site with a reinforced supporting slab made of concrete. A standard formwork and reinforcement drawing can be provided. Access steps (art. no. 860109) must be installed if the allowable difference between the top of the chamber cover and the first step is exceeded.