Coolant cooler

The cooler (1) has upper and lower coolant boxes (2, 3) i.e. coolant inlet and outlet boxes, connected with a cooler block (4), and including rigid fastening units (6, 7) and flexible fastening units (8, 9) for connecting with an intercooler via screws. The fastening units are integrally designed with the boxes at an outer contour. The fastening units lie diagonally opposite to each other. A contact surface between the intercooler and the cooler lies within a base outer contour proximity to a center of mass of the cooler in a driving direction of a motorvehicle. The boxes are made of plastic.