A fiber optic rotary joint is provided that is unaffected by variations in the optical properties of a fluid that fills its internal cavity. A proximal angled stent is configured for implanting in a side-branch vessel wherein the proximal angled stent has an angulated portion that corresponds to, the angle formed by the intersection of the side-branch vessel and the, main vessel so that all portions of the side-branch vessel at the bifurcation are covered by the proximal angled stent. The lighting module is arranged in the housing. The request requests permission for establishing a type of connection, or requests a check of a connection parameter, and specifies the first andor second network element andor the connection or connection type to be established. In that way, the flatness of the mirror can be mapped.