Two ranges of metal thread adapters, to interface between almost every thread type used on microphone stands and clamps. The first group are for with the types of stands commonly in use. The second group are for “legacy” designs.
53-217 is the most common type required. This interfaces between the American 5/8″ mic clamp thread and the European 3/8″ mic stand thread.
53-215 and 53-220 interface between the standard 1/4″ photographic thread and the European 3/8″ mic stand thread.