The pipes for subgrade drainage at the sides of a road cross-section are mainly of nominal sizes between DN 100 and DN 250 and laid in the verge or swale strip. Due to the road structure and the gradient ratio of the drain packing the possible pipe coverings are rather small and require a chamber system suitable for installation depths between 0.80 m and 1.40 m. A modular chamber of an overall height of 1.40 m for convenient inspection, SIRO-inspect S 400 meets all these requirements. The chamber body can be shortened on site, as required.