Features: Double ball head clamp with 360 degree rotation and rust resistant metal construction ensures secure mounting for 15 18mm ball heads, perfect for action camera accessories and extendable arm installations. Features double socket arms with 17mm ball head adapters and reinforced plastic iron structure (5.8cm length) for enhanced stability during extreme outdoor activities. Ideal for adventure seekers, travel photographers, and professional creators requiring reliabled mounting solution for sports cameras and mobile device holders. Optimize your action camera setups on bike handlebars, motorcycle mounts, or hiking gear while maintaining vibrations less performances. Achieve versatile shoot angles with universally compatibility across navigation systems and 17mm based phone holders, combining industrial grade materials with precise engineering. Specifications: Component: Iron + Plastic Length: 5.8cm/2.28inch Color:Black Suitable for ball heads with diameters of 15mm-18mm Package Includes: 1pcs Metal Clamp Adapter note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind befores you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color. Thanks for your understandings.