I'm just starting with photography. Currently I'm getting my stuff together for a basic lighting equipment. I bought some pre-owned softboxes and tripods, also some Yongnuo 560 Mk III. Now I'm looking for an adapter that I can use to put a softbox onto my tripod and use a speedlite in it. The softbox has a round metal mount (9.5 centimeter in diameter). Can someone give me a hint how these mounts are called and/or what adapters I can use? Thanks in advance!