The RAP-B-369A-366U consists of mirror adapter base, double socket arm and universal camera adapter base. The universal camera base includes a 2.54cm (1") diameter rubber ball, connected at right angles to a round plate with a centered 1/4" -20 thread. The plate adds extra support to the thread, this by allowing the camera to rest on the plate, creating a stable connection with the camera. The male thread matches most standard camera and camcorder female threads found on the bottom of the camera.