an electrical outlet floor box including an upright , open top cylindrical housing member , a ball ring , and a cover assembly secured to the open top of the housing member by means of the ball ring ; said housing member is embedded in a concrete floor and the upper portion removed in proximity to , and in a plane parallel to , the surface of the concrete . the ball ring insures that the upper surface of the cover assembly is parallel to the surface of the concrete floor even if the axis of the cylindrical housing member deviates somewhat from normality to the surface of the concrete floor .