Connection piece assembly unit, especially for an exhaust gas treatment device of an exhaust system of an internal combustion engine

An exhaust gas treatment device for an exhaust system of an internal combustion engine, the exhaust gas treatment device comprising:

• a device housing;
• a covering device overlapping, in at least some areas, the device housing on an outside of the device housing;
• at least one connection piece assembly unit comprising:
• a connection piece with a base area for fixing the connection piece to a carrier assembly unit of the exhaust gas treatment device;
• and
• a covering element protruding over an outside of the connection piece, wherein the connection piece of at least one connection piece assembly unit is fixed to the device housing in a mounting area of the device housing, which mounting area is not overlapped by the covering device and the covering element of the connection piece assembly unit overlaps the covering device, in at least some areas of an edge area adjacent to the mounting area;
• the covering device comprising,
• at least one layer of covering material overlapping the device housing on an outside of the device housing in at least some areas,
• at least one layer of protective material overlapping the at least one layer of covering material in at least some areas on a side facing away from the outside of the device housing,
• the at least one layer of protective material, in the edge area of the covering device, which edge area is adjacent to the mounting area, extends with an edge section beyond at least one layer of covering material towards the connection piece and in a direction away from the outside of the device housing.