SMALLRIG 1/4" Male -3/8" Male Converter Screw for Flash Mount Holder Stand (2-Pack) The adapter screw is designed with one end of 3/8" and the other end of 1/4" made of metal material, and silver plated surface. The maximum length is 20mm, and the maximum width is 16mm, suitable for all kinds gears with 1/4?or 3/8?screw hole. Note: This is a universal adapter spigot stud for the studio usage. New version precision made 1/4"-20 to 3/8"-16 stainless steel (metal) screws. Two pieces packed, easy to use.