Features: The action camera holder is make of aluminium alloys, providing a secure and stable mounting solution for your action camera. Installed on stem top caps, with a stem top screw( cannot replace stem top caps). Adaptors angles adjustable and fastened by bolt. Great positioning, comfortable viewing or monitoring device. Make surely that your action camera stays firmly even during Cycling or rough terrains. Specifications: Component: Aluminum alloys Type: Extension Stand and Screws/Extension Stand and Lamp Holder/Extension Stand and Extension adapters Extension Stand Size: about 39x23x14.8mm/1.54x0.91x0.58inch Package Includes: 1set headsets Top Extension Holder note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.