Abstract: A plastic floor box assembly for use with electrical raceways installed in concrete floors, having a plastic box, an activation ring, a cover plate for retaining an electrical outlet, and an outlet cover securable to the cover plate. The activation ring is secured within the open top of the floor box by a plurality of retaining clips, having barbs extending outwardly and upwardly therefrom. The barbs allow easy insertion of the activation ring into the box, while preventing withdrawal. In a second embodiment designed for use in tile floors, a pair of support clips are also provided on the activation ring to prevent over-insertion of the ring into the box.