GODOX S-FA Flexible Universal Four Speedlite Adapter Hot-Shoe Mount Bracket for Flash

Simple and effective. I use it in a bowens S mount adapter and works good with an umbrella too.

Works great to hold up to 4 flashes and fits well on the bracket. However, if your flash has a lock, versus a screw head to tighten it down, it will not fit. At least it didn't with my Nikon speedlights that have a lock (i.e. SB-900 and SB-910). But it works well with my Godox and FlashPoint that have a screw to tighten it down.