This can be used for the common umbrella adapters, swivel brackets, and other lighting clamps and adapters.

The diameter fits the standard 5⁄8 inch (nominal) hole found on many of the lighting accessories cited above.

One end has a 1⁄4 inch X 20 thread stud.  The other end has a 3⁄8 inch X 16 threaded hole.

The 1⁄4 inch threaded stud can be used to attach many flash hotshoe⁄shoe adapters that have a threaded 1⁄4 inch - 20 hole on the bottom.

Price: $4.50 + shipping