The invention concerns an engine-mounted fan shroud for use in a vehicle that has a shroud body supported by a vehicle engine, including an outer ring made of a first material having a first stiffness, and a bodyside seal extending from and being integral with the outer ring, with the bodyside seal being made of a second material having a second stiffness that is less than the first stiffness. A plurality of patterns is formed in a pattern region of a substrate. According to the present invention, a pressure reservoir under high pressure, in the shape of an annular groove arranged coaxially in relation to the guiding surface, is provided in said valve body. In this way a more efficient and flexible biasing of the phototransistor is possible. This wide angle of emission ensures that the secondary light is uniformly mixed into the primary light. The curable dental compositions describe herein can be utilized as dental primers, dental adhesives, dental sealants, and dental composites.