The hydraulically actuated Lutex® HKB is a wet-type, multiple plate clutch/brake combination. When the HKB is not subjected to oil pressure, the brake is engaged by the pretensioned springs. When the hydraulic oil is fed into the cylinder, the piston overcomes the spring force and is pressed against the plate package of the clutch. The platepackage of the brake opens and the clutch engages. An overlap of clutch and brake functions is impossible.