The Kupo Baby Ball Head Adapter features a 16mm socket (inside) and 28mm (outside) and allows you to mount any ball head, photo or video head on to the threaded 3/8" top.
Since most grip gear and lighting equipment uses a baby 5/8”(16mm) spigot or a junior mount 28mm (1 1/8”) receiver this accessory adds extra versatility to your gear.