Features: The diameter of the ball head is 17 millimeters, and the screw is 1/4-20 standard. It is widely used in cameras, phone stands, camera stands, and tripods. You can modify your existing device mounting base to a base that can accommodate cameras with 1/4 "-20 threaded interfaces. 1/4 screw to 17mm ball head base bracket interfaces socket connector, suitable for tripod, camera, car monitor, phone bracket, video light hose bracket, networks camera Suitable for universally 17mm tripod, stand adapter, and mobile phone and tablet stand This adapter is crafted from plastic, light weight and easy to use. Specifications: Component: Plastic + Metal Interfaces: 17mm female ball head, 1/4 external thread Package Includes: 2Pcs 17mm Female To 1/4 Male Screw Adapter note: Please allow 1mm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color of the item.