The Hawle surface box for valves is preferably used for installation in bituminous traffic areas. For height adjustment extension rings model no. 181V can be used.
Compared to conventional surface boxes the angle seat at the cover and the box provides for reduced rattling of the cover.
To avoid contact corrosion between the cover and the box, on the one hand, and to ensure that the cover comes loose easily, on the other hand, the latter is powder-coated.