Spigot Adapter Dowel Set (4 Pieces)

I believe this came with a lighting stand I purchased on Yahoo Auctions.
Sorry, I don't have calipers, so I can't provide the exact measurements.
Please judge from the images.
The image of it attached to an Avenger stand is for reference. It was a bit too thick and didn't fit into the female end of the grip head.
I can offer a ¥200 discount if you combine this with other items.