A device for coupling a coolant supply to a roller, in particular for continuous casting installations, wherein the roller is supported for rotation in a stationary pillow block, includes a sealing unit coupled to an axial roller borehole in a pressure-tight manner, and a stationary pillow block cover releasably attached to the pillow block and covering the axial roller borehole. An insert may extend through a center opening of the pillow block cover and be attached to the pillow block cover by a flange. The inside diameter of the center opening of the pillow block cover may be greater than an outside diameter of the bush to enable a removal of the sealing unit from the roller borehole without removal of the pillow block cover.