Abstract: An apparatus which attaches a first device within a cavity of an anchor without using inserts, flanges, or adhesives is disclosed. Flexibility in positioning the device relative to the anchor is provided regardless of whether the anchor cavity or the device is threaded. A keeper having two rows of teeth, each row being substantially perpendicular to the threads, is mounted between the device and anchor and rotates under a force exerted by a pin so that only one of the two rows engages the thread channels. The force exerted by the pin also causes the keeper to pivot about a pivot end which is specifically shaped to prevent binding upon removal of the device from the cavity.