Abstract: A two-part device, automotive lighting unit and method of manufacture are described herein. A two-part device includes an assembly. The assembly includes a first part having a first fixation face and a second part separate from the first part. The second part has a second fixation face. The first and second parts are arranged adjacent one another with the first fixation face in contact with the second fixation face. The assembly further includes a circlip fixation position that has a rounded shape transverse to the fixation face. The two-part device also includes a circlip, which engages the rounded shape at the circlip fixation position, fixing the first and second parts together.