Amazon.com : Neewer 2 Pieces Standard 1/4 to 3/8 inch Metal Male Convertor Threaded Screw Adapter Spigot Stud for Studio Light Stand, Hotshoe/Coldshoe Adapter, Ball Head, Wireless Flash Receiver, Trigger : Electronics
VMB TV-07 Spigot Adapter 55mm-29mm – Thomann United States