All gear are 1/4 inch. Widely using on camera accessories such as Tripod, Monopod, Ballhead, Light stand, Video light. It is a definitely strong tool for bringing a better usage to your photography rigs! 5 Pieces 1/4 inch to 3/8 inch Female Spigot Adapter. Specifications: design for 1/4 inch to 3/8 inch female spigot adapter. Dimensions: max length 28 mm, max width is 16 mm. Side: 1/4" Female thread, 3/8" Male thread. 5 Pieces 1/4 inch to 1/4 inch Male Threaded Screw Adapter Specifications: design for 1/ 4 inch male threaded screws. Dimensions: max length is 20 mm; max width is 16 mm, Material: made of metal and silvery plated surface. 5 Pieces 1/4 inch to 3/8 inch (Female to Male) Screw Adapter Specifications: design for 1/4 female-3/8 male screw adapter. Dimensions: male thread: 3/8", female thread: 1/4". Material: metal, silvery plated surface. Package Content: 5 x 1/4"Female-3/8"Female Spigot Adapter 5 x 1/4"male-1/4"Male Screw Adapter 5 x 1/4"Female-3/8"Male Screw Adapter 1 x Free Cleaning Cloth

• That base is UNC 3/8 screw (PTZ camera or parent), can be connected to the UNC 1/4 "platform or quick release plate.
• It suits for the bottom screw hole is 3/8 inch and the ballhead screw hole is 1/4 inch screws.
• Thread Adapter with 1/4" female to 3/8" male, compatible to Lens Plate Button Heads, Arca Swiss Type Button Heads.
• Made of metal, solid and durable, fit as well as original reducer.
• For many purpose of camera tripod or quick release plate. Please check the size before ordering.

That base is UNC 3/8 screw (PTZ camera or parent), can be connected to the UNC 1/4 "platform or quick release plate.Longruner