A circular plug connector unit for shielded electrical cables, having an insulating body that is enveloped by a shielding sleeve, wherein plural electrical socket shaped plug contacts and/or pin shaped plug contacts are arranged in receiving cavities in the insulating body, wherein the shielding sleeve is interlocked with the insulating body. The plug side end of the shielding sleeve includes an even number of axially extending sleeve segments which are separated by longitudinal slots which are advantageously configured as sleeve segments that are short in axial direction and sleeve segments that are long in axial direction. Sleeve segments which are arranged in sequence advantageously have a uniform radial offset relative to each other in an alternating direction, wherein the sleeve segments of two identically configured shielding sleeves are insertable into one another with a rotational offset in circumferential direction of 360° divided by a number of the sleeve segments.