An arrangement having an impeller that rotates about an axis and a stationary diffuser located downstream with guide vanes. The impeller has an inlet for an axial supply flow and an outlet for a radial out-flow, wherein radially and axially extending rotor blades are arranged between a wheel disc and a cover disc of the impeller. The impeller channels are separated from one another in a circumferential direction. The diffuser extends substantially radially along a main flow direction and has an axial channel width. The diffuser has a diffuser inlet and outlet, wherein guide vanes extending axially along a blade vertical direction and radially along a through-flow direction are arranged between the wheel disc side and the cover disc side of the diffuser, which separate the guide vane channels from one another. An inlet edge angle is smaller on the cover disc side than on the wheel disc side.